That you may know that you know.

There are many people who have doubts about their salvation. One of the key words in John's epistle is "know". In the four verses from 2:3 - 6 John uses the word "know" four times. He says that we know that we have come to know Him if we keep His commands. Does that mean that we are trusting in our obedience for our salvation? If that were the case then we would not know that we know. It is not our obedience that we are trusting in but rather it is our obedience shows that we do trust in His finished work.
The problem of trusting in our work is that we will never know until our work is completed whether or not we are saved. However, we trust in Christ's finished work. It is done. We know that it is complete and we can have that assurance because of Him. Yes, we can know that we know.