One of the verses I use during the semester is John 3:18 - "He who believes in Him is not judged; he who does not believe has been judged already, because he has not believed in the name of the only begotten Son of God." Of course, John 3:16 we already know - it is a statement of God's love, and how that love is shown. Verse 17 helps with the context ("For God did not send the Son into the world to judge the world, but that the world might be saved through Him."), by showing what Jesus came to do. This is important to state, because Jesus did come to deliver salvation as a sacrifice; on His second coming, Jesus will fulfill the promise by setting apart those who are saved from those who are not.
Verse 18, however, provides a very clear statement about our part in Christ's salvation. If He did not come to judge, then how are we to be judged? Jesus, speaking to Nicodemus, points out that, in the end, it is we who judge ourselves. If we accept Christ, then we will not be judged; when the time for the final judgement of all men comes, and our moment to face God is at hand, Jesus stands besides us to say our debt has been paid. If we do not accept His salvation, then we face God alone, and nothing will be good enough to substitute for our sins.
So, the question of our judgement before God is not, as most people think, some far off event; no, it is something that is being lived out right now. Once we accept that belief, once we accept Jesus' substitution for us, then the question of whether we will go to Heaven is answered. We will not be perfect, we will not be done growing, but we will not be judged. For one decision to see us into eternity in Heaven, the choice is worth it.
But of what value is this in our day-to-day lives? Well, certainly it is important to know how and why our faith and our salvation works. Perhaps more important, however, is living in such a way that we show by demonstration that believing in Jesus and His name is actually worth it. Think of it this way - we are walking advertisements for Christ. If people look at us and say, "Well, there's no difference between him and us, so believing in Jesus must not really be worth anything," then we have not been a good advertisement. If people say, "Wow, I want what he has!" then we've done our part, by showing the believing make a difference. That's why it's important to know John 3:18, because it helps give us a reason to keep on living a righteous life, and that is what it's all about!
Love,
Dad