I literally quoted Him.
John 3:16 are HIS words.
Here are a few more from the same passage, a conversation with Nicodemus.
“Most assuredly, I say to you, unless one is born again, he cannot see the kingdom of God.” Nicodemus said to Him, “How can a man be born when he is old? Can he enter a second time into his mother’s womb and be born?” Jesus answered, “Most assuredly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God. That which is born of the flesh is flesh, and that which is born of the Spirit is spirit. Do not marvel that I said to you, ‘You must be born again.’ “
John 1: 11-13 explains it well
“He came to His own, and His own did not receive Him. But as many as received Him, to them He gave the right to become children of God, to those who believe in His name: who were born, not of blood, nor of the will of the flesh, nor of the will of man, but of God.”
Whoever wants to be forgiven, to be sure that they are born of God is welcome to come to Jesus and receive Him, to believe on Him, putting their faith in Him. He has promised that He will not turn anyone away who sincerely comes to Him.
Hear some more of His words from His conversation with Nicodemus-
“ He who believes in Him is not condemned; but he who does not believe is condemned already, because he has not believed in the name of the only begotten Son of God. And this is the condemnation, that the light has come into the world, and men loved darkness rather than light, because their deeds were evil.”
John 3:18-19
And as John himself testified
“He who believes in the Son has everlasting life; and he who does not believe the Son shall not see life, but the wrath of God abides on him.”
John 3:36