His parents said this, because they feared the Jews. For the Jews had already agreed that if anyone confessed that He was the Christ, he would be put out of the synagogue.
Whoever believes in the Son of God has this witness in himself. Whoever does not believe God has made Him out to be a liar, because he does not believe the testimony that God gave about His Son.
I have written these things to you who believe in the name of the Son of God, that you may know that you have eternal life, and that you may continue to believe in the name of the Son of God.
And we know that the Son of God has come and has given us understanding, so that we may know Him who is true, and we are in Him who is true —His Son Jesus Christ. He is the true God and eternal life.
Because of this, if I come, I will bring up what kinds of works he does: ranting against us with malicious words. Not content with that, he does not accept the brothers, and stops those who want to, and throws them out of the church.