There are a number of different ways that we might answer this question but one of the more helpful is by saying that the reasons that I know God exists are the same as the reasons I know that Napoleon existed. You might ask me, ‘Did you ever see Napoleon?’ To which I might reply, ‘No, but I could have if I hadn’t been born too late. We can’t live in every moment and in every place of history’.
It’s similar when it comes to the question of how we can know God exists. The man Jesus claimed to be God. His actions bear out that claim. He healed the sick, exorcised demons, stilled the storm at sea, brought the dead back to life, and died and rose from the dead himself.
One famous Christian, C. S. Lewis, once said that Jesus is either Lord, lunatic, or liar. These are the only three options we have available to us when making up our minds about him. He may have been a lunatic – that is, he thought he was God but wasn’t. He may have been a liar – that is, he knew that he wasn’t God but said that he was. But from the evidence we have available to us, neither of those options seem to fit. What do you make of Jesus? Perhaps you might like to read through one of the biographies of Jesus in the Bible – Matthew, Mark, Luke or John – and ask yourself: Is he lunatic, liar, or Lord?