"For God did not send his Son into the world to condemn the world, but to save the world through him." (John 3:17 NIV)
The verse preceding this is one most everybody can quote, "For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life." (John 3:16)
Both of these verses point out something very clearly, that almost no one will argue with. Jesus came to save this world. But save it from what? I ask that because many in our world want verse 17 to say that Jesus didn't come to condemn anyone, therefore, there is no condemnation. But if that's the case, I ask the question again, save the world from what?
The world needed saving (and needs saving today) because it stands condemned already. Condemnation comes about because of our sin. How do we know that? Jesus clearly says it over and over including these words in John 12:48 "There is a judge for the one who rejects me and does not accept my words; the very words I have spoken will condemn them at the last day." Christ had no need to condemn an already damned world, He had a need to bring it salvation. But He pointed out that those who reject Him and the salvation He offers will stand condemned for eternity if they fail to accept His words. If we were we not cut off from God by our sin(s), we would not need saving.
I agree with a portion of the thought process of these people, that other people are not in a position of judgment to determine whether or not one stands condemned by God, but that absolutely doesn't remove any condemnation that God puts on someone because of their transgressions.
Most people know John 3:16, yet with some their understanding stops there. We carried it one thought further with John 3:17 above. Now, let's look at John 3:18. "Whoever believes in him is not condemned, but whoever does not believe stands condemned already because they have not believed in the name of God’s one and only Son." So as we said, Jesus and His power to save was (and is) necessary because the world "[stood] & stands condemned already" apart from Him.
If you combine all the teachings in the New Testament, and look at everything Jesus taught personally and through His inspired Apostles, we come to understand that believing in Him requires belief coupled with obedience. Believing only, with no faith, no commitment and no obedience is worthless (James 2:18ff). Scripture says even the demons believe, (James 2:19) but in no way does that justify them so as to avoid condemnation and punishment.
Using John 3:17 to say there is no condemnation for sin from Christ, therefore man has no right to speak out against sin is tryin to bend scripture around a corner for their own self righteousness. Such positions ignore the adjacent verses and fly in the face of the entire concept of the New Testament teaching, the Good News, salvation from the consequences of our sin(s).
Breaking God's laws as well as intentionally ignoring God's commands automatically brings about condemnation. Mark 16:16 says, "Whoever believes and is baptized will be saved, but whoever does not believe will be condemned." Salvation comes through belief and obedience. Condemnation comes through disbelief and rejection.