His parents said this because they were afraid of the Judean leaders. For the Judean leaders had already agreed that anyone who professed Yeshua to be Messiah would be thrown out of the synagogue.
The one who trusts in Ben-Elohim has the testimony in himself; the one who does not trust in God has made Him a liar, because he has not believed in the testimony that God has given about His Son.
And we know that Ben-Elohim has come and given us insight, so that we may know Him who is true—and we are in Him who is true, in His Son Yeshua the Messiah. This One is the true God and eternal life.
So if I do come, I will call attention to what he is doing—slandering us with wicked words. Not even content with that, he refuses to welcome the brethren, and even forbids those who want to do so— throwing them out of the community!