Why is it that, even though we are supposed to do God's will to be saved supposedly, why does Jesus say that those who believe will not be judged, even though you were saying we are all judged? In that case, then it's like a paradox because everyone is judged even those who are believers, but those who are believers are not judged?
I assume you are referring to: "I have come as a light into the world, that whoever believes in Me should not abide in darkness. And if anyone hears My words and does not believe, I do not judge him; for I did not come to judge the world but to save the world. He who rejects Me, and does not receive My words, has that which judges him -- the word that I have spoken will judge him in the last day." (John 12:46-48).
Jesus' purpose in coming into the world was not to condemn the world. It already stood condemned. Jesus came to save the world from its own condemnation. Thus, Jesus said that if someone refuses to believe in him, he does not need to do anything because the Gospel message he brought with him condemns him without any direct action on Jesus' part.
There is also a difference in time frame. Jesus was talking about his existence in the world versus the final judgment when the world will come to an end. Believers at the end will not face judgment (condemnation) because they will be found righteous before God.
Well, I actually was still talking about John 3:16 because it says whoever believes in him shall have eternal life, but then in Mathew 7:21 it says that not everyone who calls out on him will receive the kingdom of heaven, even though they say they cast out demons in his name, etc. It says that only people who do the will of God will receive the kingdom of heaven. I guess what I'm trying to say is, isn't it kind of like a paradox? In John 3:16 Jesus says if you believe in him you are going to have eternal life and won't be judged, but in Mathew 7:21 he basically says that just because you believe in him doesn't mean you are going to make it to heaven, but you have to do God's will and if you don't then you will still be judged, even though you are a believer. But believers aren't judged according to John 3:16. And it goes in circles like that.
"And as Moses lifted up the serpent in the wilderness, even so must the Son of Man be lifted up, that whoever believes in Him should not perish but have eternal life. 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. For God did not send His Son into the world to condemn the world, but that the world through Him might be saved. 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. For everyone practicing evil hates the light and does not come to the light, lest his deeds should be exposed. But he who does the truth comes to the light, that his deeds may be clearly seen, that they have been done in God" (John 3:14-21).
A part of the problem is that some translations obscure an important point in John 3:16. The "should" in "that whoever believes in Him should not perish" is in the subjunctive mood. This means it is a potential action, a probability but not a certainty. Thus, this passage is not stating that belief absolutely assures salvation. Belief ought to lead to salvation.
Unlike English, "belief" is not seen as independent of "obedience" in the Greek. This can be seen in "And to whom did He swear that they would not enter His rest, but to those who did not obey? So we see that they could not enter in because of unbelief" (Hebrews 3:18-19). To disobey is to disbelieve. To disbelieve is to disobey. Therefore, it ought not be strange that Jesus charges those who claim to believe in him with disobedience. In another verse, Jesus said, "But why do you call Me 'Lord, Lord,' and do not do the things which I say?" (Luke 6:46).