Believing is all. Do you believe? Do you believe in Christ? It may be that someone answers, ‘Yes I do. I believe there was a person named Jesus Christ’ and that you might even go so far as to say, ‘I believe he is God. I believe he is Lord,’ but that isn’t enough! You can believe that without ever coming to him, without being forgiven by him, without ever having a place in heaven or real spiritual life, because believing is more than simply assenting in your mind to the existence of Jesus Christ, or even that he is God. You have to believe, more fully, in his person. It is to understand that he is God who came to be a Saviour. He has done this for people like me. I could never enter into heaven without him. It is not just an assent; it is a conviction.
But believing also includes this: you have to believe his call, and the terms of salvation. You can’t be saved, you can’t be forgiven, you can’t be cleansed, with a loose assent which just drifts through life with no commitment to him. I must believe what he says when he says, ‘Repent and believe, or else you’re lost’. I believe those things, and because I believe them, I come to him. I don’t trust in anything in myself, any imagined goodness. I trust in him and him alone.
How can Christ say that the unbelieving are condemned already? You may think that whether a person goes to heaven or to hell, waits to the end of life, when the books are opened, and each one is weighed in the balance: how much good has he done? How much wrong has he done? Only at the very end will you know. No, says this verse, you know whether a person is going to heaven or hell long before the completion of their life, because it doesn’t depend on what we do, it depends on whether we believe in him, or reject him. No good works that may be done during the rest of his life will make any difference or need to be taken into account by God in deciding our destiny; faith alone is what matters.