If I told you earthly things and you don't believe, how will you believe if I tell you heavenly things?
People are foolish. Unless they can understand all the processes by which God is working, they won't accept it. I can't explain to you how that believing in Jesus Christ can cleanse you of your sin and cause you to be born again and become a child of God. All I can tell you is it will. It works. That's what God has ordained. Jesus, hanging on the cross, was bearing the judgment of God for your sins. "All we like sheep have gone astray, we turn, everyone of us, to our own ways. And God has laid on Him the iniquities of us all" ( Isaiah 53:6 ). "As Moses lifted up the serpent in the wilderness, so must the Son of man be lifted up. " And Jesus, hanging there on the cross, was there taking the judgment of God for sin, dying for our sins, dying in our place. And even as those in the days of Israel looked at the serpent and lived, so we, by looking at the cross in faith and in trusting in Jesus, live. We have eternal life. And so, it was quite an interesting parallel, symbolism that God had established.