"We know that we are of God, and the whole world lieth in wickedness. And we know that the Son of God is come, and hath given us an understanding, that we may know Him that is true; and we are in Him that is true, even in His Son Jesus Christ. This is the true God, and eternal life" (1 John 5:19-20).

In the early Church there was nothing of the uncertainty which we find among Christians now. They knew what they were, and it was on the authenticated facts concerning Christ that they rested this certainty. No one then thought of saying, 'I believe, but I am not sure whether I am born of God;' for they took for granted that 'whosoever believeth that Jesus is the Christ is born of God.' They did not analyze their own faith to ascertain how far it was of the right quantity and quality. They never thought of themselves at all, but only of Him who, though rich, for their sakes had become poor. All the epistles take for granted that they knew that they were Christians; nor is anything written there to encourage them to suspect themselves, or to teach them the art of doubting. Nothing is there addressed to them to lead them to make much of their doubts, or to believe in their own faith as the true way of deliverance from doubting. 'We know', was the apostle's language; 'We know', was the response which that language met with from all to whom he wrote.

The frequent use of this expression in the epistles lead us to make inquiry as to its actual import, and its bearings on ourselves. It is undoubtedly the language of certainty; and, as such, let us see in what connection it is used.

It is used respecting things past, things present, and things future, all of which are represented as being absolutely certain to the person knowing.

1. The Past - 1 John 5:20, 'We know that the Son of God is come'; 3:14, 'We know that we have passed from death unto life.' These two things, one relating to the Son of God, and the other to the Christian, are spoken of as equally past, and as equally certain objects of sure knowledge.
   
2. The Present - 1 John 2:18, 'We know that it is the last time'' 2:3, 'We know that we know Him'; 2:5, 'We know that He abideth in us'; 5:19, 'We know that we are of God'. All these things are represented as ascertained and conscious certainties, regarding which there could be no doubt whatever. This was the true state of the early Church universally. We do not read of anything short of this, - anything corresponding to the state of doubt, and gloom, and uncertainty, in which we find so many Christians now.
   
3. The Future - 1 John 3:2, 'We know that when He shall appear, we shall be like Him.' The early Christians counted the one as sure as the other. Their future was not darkened with the clouds of uncertainty: clouds of tribulation might envelope them, but their future was glorious.
   

We find the expression 'I know' used in a similar way in other parts of Scripture. 2 Tim. 1:12, 'I know whom I have believed.' We find the words 'Ye know that ye were not redeemed with corruptible things.'

All these passages show us what the condition of personal certainty was which the early Church enjoyed, of which we ought to be in possession. A Christian is not one who 'thinks'; or 'hopes,' or 'trusts' that he is forgiven and accepted, but who knows it as certainly as he knows the facts regarding Jesus, His death and resurrection.

How did they come by this certainty?

They got it out of the promise which the gospel embodies. That gospel consists of two parts or testimonies, or rather a testimony and a promise. The testimony relates to the Christ of God, His person and His work; and the promise is, that whosoever believes the testimony is not only entitled, but commanded to draw the conclusion that he has eternal life. A testimony without a promise would not have done it; it would have merely brought us into the position of men who see that their salvation is a possibility. They could not, from the testimony alone, draw the conclusion, 'I have eternal life;' but the promise annexed to the testimony, declaring that every one who receives the testimony is saved, enables them at once to draw the personal conclusion. Thus we see that, while personal assurance is not the first thing in faith, it ought to follow immediately, and will do so where the gospel is rightly understood.

It is out of this annexed promise that our assurance comes, and not out of subsequent acts, or feelings, or experiences of our own. He who has not this assurance must not be believing the very gospel, but either more than it, or less than it. He who takes the whole gospel, both testimony and promise, knows that he has eternal life.

But, let us inquire a little further into this apostolic and primitive certainty. Both John and Paul use this word 'We know', frequently. They use it not merely as apostles, but in the name of all believers. They do not merely say I, but we (1 John 3:14; 2 Tim. 1:12). It is the language of certainty, not of opinion or conjecture. Let us ask, (1) What is the certainty? (2) how they got it? (3) how they kept it? (4) how they used it?

I. What is the certainty? - We know that we are of God, - that is, that we belong to God, that we are His children. This is, -

1. Very definite. - There is no mistaking what it means. We have passed from death to life; no longer condemned children of wrath, but God's property, - God's sons, God's heirs. Not generally 'we are Christians,' but 'we are of God.'
2. Very decided. - It is not 'We hope we are of God, We think we are, We trust we are, We are inclined to believe we are, but 'We are'. There is no want of decision here, no vagueness, no ambiguity, no hesitation, no 'if', no 'perhaps', but 'we know.'
3. Very personal. - It was something regarding themselves individually, not merely as classed with a certain body generally, but a personal thing, of which they were as cognizant as of the family, or city, or nation to which they belonged. Paul knew, and John knew, and all the early Christians knew that they were of God.

Yes, this was the apostolic watchword; 'We know that we are of God.' It was the Reformation watchword; it must be ours.

II. How they got it. - In believing. It was not that they first believed themselves to be of God, and so were of God. They believed what God has told them concerning His Son, that Jesus was the Christ. They believed the record, the true record, concerning the eternal life which was in Him. In believing that record they became sons of God and they knew this. The assurance of their own sonship was the necessary and inseparable consequence of believing the record, the gospel, the report. They got this certainty at once, - not after passing through a long and mysterious process; not after summing up all their own goodnesses, and being satisfied with the quality and the quantity of their faith; not as a result of tedious metaphysical investigation into their spiritual state, - but as the simple and inevitable inference from their believing the gospel.

III. How they kept it. - They held the beginning of their confidence steadfast to the end. They continued to believe all that they did at first, and just in the same simple way. That which gave them peace and assurance at first, continued to do so to the last. Not as if it were a light matter whether they became holy or not. Far from this. That gospel which they believed taught them that they were to deny ungodliness and worldly lusts. The peace they got was a holy peace, and could not exist in conjunction with an unholy life. The love of God out of which that peace had come to them was a holy love, and the indulgence of sin was incompatible with the belief of it. That sin in a true saint does not alter his standing as a pardoned man in the sight of God, is true; but it comes between him and God, and shuts God out. It may not tell upon God's feelings toward men; but it must tell upon man's feelings towards God, and also upon his knowledge of God's feelings towards him. The assurance does not come out of our holiness; yet it cannot be maintained save in connection with a holy life.

IV. How they used it. - Not for pride, self- seeking, or vain-glory. It did not destroy humility and meekness in them, nor did it lead to careless living. It brought with it no contempt of others, and no ostentation in their religious profession. They used it in none of these ways, nor for such purposes. It was to them,...

1. A humbling truth - That God should have given them sonship was humbling; that He should have given them the assurance of it was more humbling still; for it brought out more fully all their own unworthiness, in contrast with God's boundless love. Compassed about with such love, so free and great, how could they be proud? Where is presumption? It is excluded. By what law? of faith and certainty.
2. A quickening truth - It had true life in it, true power. It stirred, it roused, it animated, it nerved. Uncertainty as to our relationship to God is one of the most enfeebling and dispiriting of things. It makes a man heartless. It takes the pith out of him. He cannot fight; he cannot run. He is easily dismayed, and gives way. He can do nothing for God. But when we know that we are of God, we are vigorous, brave, invincible. There is no more quickening truth than this of assurance.
3. A gladdening truth - This needs no long proof or illustration. What gladness is contained in these simple words, 'We know that we are of God!' Until we can say this, where is joy? When we can say this, where is sorrow? It has fled away. What can cast us down?
4. A sanctifying truth - Yes, it sanctified the early Christians; and this in two ways: (a) separating them from a world that knew nothing of his love; (b) making them inwardly holy, like Him to whom they knew that they belonged. 'Now are we the sons of God...He that hath this hope in Him purifieth himself.'

Are you sure? Can you say, I am of God? Has your gospel brought you certainty? or has it left you in non-assurance, a prey to doubt? Then what has it really done for you?

The Bible is the book of certainties. It gives not uncertain sound anywhere. It does not speak the language of doubt, or speculation, or conjecture, or opinion, but of certainty. Its object is to place us on the same footing of certainty, absolute certainty; enabling us to say not merely I think, or I judge, but I know; enabling us to say without faltering, yet without boasting, I possess the true, the real, the certain, the authentic. Our certainty from such a source is as sure as demonstration, because it rests on the authority of the God only wise.

This epistle is written (as we have seen) in the language of certainty. 'We know' is its motto, its burden from first to last. 'Ye have an unction from the Holy One, and ye know all things' (2:20). 'We know that we have passed from death to life' (3:14). 'We know that we are of God' (5:19). 'We know that the Son of God is come' (5:20).

In our text there are three clauses or statements, each of them connected with 'we know'. Thus we have three certainties here: to each of them let us look.

1. We know that the Son of God is come. - this is the central point of earth's history, the most real, and certain, and productive of all its facts and events. On it everything turns, whether men see it or not.
1. There is such a being as the Son of God. - He is not merely a son, but the Son, the eternal Son, the only begotten Son, the well-beloved Son; one with the Father.
2. He has come. - Not merely He is, but He has come down to us in very deed. The word implies, remaining as well as coming. It is not, He has visited us, He has come and gone; but, He has come to us, and is with us. He has arrived, not to depart, but to remain.
3. He is Jesus of Nazareth. - A very man is He. Born at Bethlehem, brought up at Nazareth, the son of Mary, Jesus, who went out and in amongst us. The Word was made flesh, and dwelt among us.
4. We know this. - It is the most certain of all certainties; an event beyond the shadow of a doubt; the surest of all sure facts in earthly history. We know it on God's authority and on man's. Divine and human testimony unite here. Word and deed make us sure of this.
   

   Ah, this is knowledge! The like of it is not to be found elsewhere. This is the knowledge that satisfies, gladdens, and gives us a foundation to rest on, - THE SON OF GOD HAS COME.

2. We know that He has given us an understanding that we may know Him that is true. - for the meaning of 'understanding' we refer to Eph. 1:18: 'The eyes of your understanding darkened.' Christ is the giver of the new mind, whereby we discern the truth. He is, (1) Renewer; (2) Teacher; (3) the Wisdom itself. He is the knowledge, and He gives the power of knowing. 'Who teacheth like Him?' He is the opener of the eye and ear. He that is true is evidently the true One, or true God. 'This is life eternal, that they might know Thee, the only true God,' to give us a mind capable of knowing and comprehending this true God. It is not a God that we need to know, but the God, the one living and true God. There is no knowledge of God out of Christ, apart from Christ, or without Christ. Where the knowledge of Christ is not, there is utter ignorance of God, - the worship of a false or an unknown god. False worship is a serious thing, a fearful sin, a hideous blasphemy. Falsehood touching God is infinite dishonour. Misapprehension of God is the root of all idolatry; and worship under such misapprehension is idolatry or superstition. It is the true God that is to be worshipped, none else. He will not give His glory to another. Nor will the knowledge of any false god fill or pacify the soul. It is only that God whom Jesus of Nazareth revealed that will suffice for the human spirit.
   
3. We know that we are in Him that is true. - To be in Him is to be out of the world, and out of self. We are to be in Him as the flower is in the garden, as the star is in the sky, as the graft is in the olive tree. We are to be rooted and built up in Him. Here it is not near Him, nor on Him, but in Him. We dwell in Him, and He in us. We are in Him as the true God; as such He is our God, our habitation. Thus we are compassed about with Him as the earth is by the air; He compasses us about. It is not merely that in Him we live, and move, and have our being; but much more than this, something of another kind; something that involves spiritual life, fellowship, love, and everlasting blessedness. But it is added, 'in His Son Jesus Christ.' We are not only in the Father, but in the Son, as we read (1 Thess. 1:1), 'The Church of the Thessalonians which is IN God the Father, and IN the Lord Jesus Christ.' It is this inbeing, this indwelling, this participation or fellowship, that is our true standing and privilege.

1. This knowledge saves. - There is no salvation without it. It is saving knowledge. In knowing the true God we are saved.
   
2. This knowledge gladdens. - False knowledge of God, or the knowledge of a false god, imparts no joy; this does. It is joy to know the true One.
   
3. This knowledge purifies. - Error or falsehood cannot deliver from sin, cannot purify the soul. All error is impurity, unholiness. All truth is good, and all truth respecting God sanctifies, expands, elevates.
   
4. This knowledge makes us useful. - It is like a light or a fire within us that cannot be hidden. It is like a power within us which cannot but work. It is irrepressible.

Acquaint thyself with God, and be at peace; thereby good shall come unto thee. He has revealed Himself in Jesus Christ, His Son. Blessed the man that knows Him. Unhappy he that knows Him not. Better that he had been a beast; better that he had never been born.