Beloved, we are God’s children now, and what we will be, has not yet appeared; but we know that when He appears we shall be like Him because we shall see Him as He is. And everyone who thus hopes in Him purifies himself as He is pure. I John 3:2-3.
While Jesus was on earth, Mark tells of Jesus changing in appearance. And after six days Jesus took with him Peter and James and John, and led them up a high mountain by themselves. And He was transfigured before them, and His clothes became radiant, intensely white, as no one on earth could bleach them. Mark 9:2-3.
Is this what it means, we shall be like Him and see Him as He is? How can we become pure? God commands that we believe in His Son Jesus Christ and love one another. It is when we believe in Him, and walk through life with Him, we become pure. This is what abide in God means, a close relationship. When every word we say and every action glorifies our Lord Jesus Christ, we abide in Him. This is only possible through the Holy Spirit that He gives us.
Everyone who goes on ahead and does not abide in the teaching of Christ, does not have God. Whoever abides in the teaching has both the Father and the Son. I John 2:9.
And the effect of righteousness will be peace, and the result of righteousness, quietness and trust forever. My people will abide in a peaceful habitation, in secure dwellings, and in quiet resting places. Isaiah 32:17-18.
And this is His commandment, that we believe in the name of his Son Jesus Christ and love one another, just as He has commanded us. Whoever keeps His commandments abides in God, and God in him. And by this we know that He abides in us, by the Spirit whom He has given us. I John 3:23-24.