I would submit that Christ knew God, in the same manner that you know Christ. In the same manner that Christ lives in you. Not in a physical sense, but in a spiritual one. Thus to know God is one thing, but to know that God exists is quite another. For the first is a visceral thing, and the second is a cerebral one. The heart “knows”, what the mind can’t.
Your heart can tell you that God exists, but your mind can never be certain of it. And the world is full of people whose hearts have convinced their minds that they’re right. It’s not my intention to prove any of them wrong. It’s simply my hope that they’ll temper their convictions with the humility that comes with knowing that they might be wrong.
No, I wouldn’t. The world doesn’t appear to be filled with people who believe. Rather, the world IS filled with people who believe. If the people are real, then believing is something that they’re doing. It’s a conscious act. On the other hand if they’re simply an illusion, then believing is an attribute that they have. It’s a characteristic that they possess.
Actually this is a classic case of Catch-22, if you’re a conscious being like I am, then you can’t be certain that God exists. On the other hand if you’re not a conscious being, then you still can’t be certain that God exists. Thus what applies to me, applies to you as well.
Also, if you’re an illusion, then I’m basically arguing with myself, in which case it’s quite obvious, that if I can’t know something, then you can’t possibly know it either.
But even if you are a conscious being like me, then you face the exact same dilemma that I face, namely that you can’t be certain of the objective existence of anything outside of your own mind. In which case the argument still applies.