John 3: 0 Jesus answered and said to him, “Are you the teacher of Israel, and do not know these things? 11 Most assuredly, I say to you, We speak what We know and testify what We have seen, and you do not receive Our witness. 12 If I have told you earthly things and you do not believe, how will you believe if I tell you heavenly things? 13 No one has ascended to heaven but He who came down from heaven, that is, the Son of Man who is in heaven. 14 And as Moses lifted up the serpent in the wilderness, even so must the Son of Man be lifted up, 15 that whoever believes in Him should not perish but have eternal life. 16 For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life. 17 For God did not send His Son into the world to condemn the world, but that the world through Him might be saved.
18 “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.
In the above, the blue is what God did to save mankind
The green is what we must do to be saved
and the red is what is done to remain lost.
John shows us what is meant by the green in the very first chapter of his gospel.
John 1: 12 But as many as received Him, to them He gave the right to become children of God, to those who believe in His name: 13 who were born, not of blood, nor of the will of the flesh, nor of the will of man, but of God.
its not a work to receive a gift. But it does take faith to receive the gift. You will not receive something you do not trust. John also tells us why those who do not receive him fail to receive him in unbelief.
John 3: 19 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. 20 For everyone practicing evil hates the light and does not come to the light, lest his deeds should be exposed.
thats why John is so amazing. He brings to truth of the gospel to light in such a meaningful pure way