1 John 3:3 And every man that hath this hope in him purifieth himself, even as he is pure.
When we see Jesus face to face we will be like him, that is, we shall be pure, with holy love and righteous perfection. What a day that will be! Until then, God implants hope in the heart, the hope of seeing Jesus in His brilliant glory and becoming like Him.
We are not already pure, as we shall become, but we are in the process of becoming pure. It is not we who are making ourselves better people through the self-improvement efforts of the sinful flesh, for nothing can be done to improve the flesh except to crucify it. It is the hope in us that is doing the purifying. it is ”Jesus Christ in you, the hope of glory [Colossians 1:7].” Hope purifies. God promises hope and a purifying process while we are still alive on earth waiting for full revelation.
We are called upon to trust the indwelling Spirit through the Word of Gospel and the ”school of experience” to grow and develop us in the purifying process. He knows what He is doing, and He will do what is right and good for us. Just trust.
God loves a pure heart, and so do we. So He makes this promise, and won’t stop purifying until the goal is reached.