1 John 3:19,20 - By this we shall know

3:19

This and the following verse talk about assurance. One of the tactics of false teachers is to sow doubt and guilt in the minds and hearts of those they seek to ensnare. The gnostics would have used this tactic, seeking to plant a seed in the Christian’s mind that they are lacking something, that they are not really acceptable to God. John here gives two answers to dealing with this attack, the one in this verse calls on us to look at the fruit of our life. If we are believing in Christ and are loving our fellow Christians, in word and in deed, not word only, then that is a clear objective proof that the Spirit is genuinely working in our lives. The gospel has nothing to do with salvation by works, but it has everything to do with salvation that produces works. So if the fruit of the Spirit is apparent in our lives, then it is clear that God is in our lives. This is not speaking about perfection, but it is speaking about fruit.

3:20

Now John addresses the problem of the condemning heart. When we come to Christ we become increasingly aware of our sinfulness. Now the grace of Christ is greater than our sinfulness, but even so there will be times when we are acutely aware of our unworthiness in ourselves. Then we may feel condemned. So what are we to do about it? John tell us that “God is greater than our hearts and He knows everything”. God has justified us through the blood of Jesus. This was an objective act with real and lasting consequences. Moreover, Jesus died for us while we were still sinners. God knew everything that there is to know about us, including the full extent of our sin and sinfulness. Knowing this He sent His Son to die for us as a completely effective sacrifice. Ultimately it is God who judges us, not our hearts, and on the cross the judgement is made clear. Our sin is completely worthy of condemnation and death, and Jesus has fully paid that price. So we are completely and perfectly justified by God. It is God who decides the verdict, not us, so we can be confident in His presence.