Actually, no.
One can believe something without being "absolutely certain." Every person walking on this earth does it every day, from believing one politician is more honest than another to believing the weather will be good tomorrow because the sky is red tonight (and you don't even need Matthew 16:2 for that, nor would a bad forecast disprove it).
He himself didn’t leave the possibility open that He was simply a good teacher or even a prophet. He either was (is) what He claimed to be, or He was a madman.
Or what He actually said was misreported...whether intentionally, through misunderstanding, poor recollection, etc. There's always that possibility, too. Probably others.
Myself? I choose to believe.
I've never found belief to be a choice.
I could never manage to convince myself to believe the sky is green, or whatever. I find it odd to hear people talk about choosing their religions.
Gondring: “I’ve never found belief to be a choice.”
You have my sympathy. Perhaps someday you’ll make what I believe is the right choice. Perhaps you feel the same about me, that I deserve sympathy for believing in what you think is a fantasy.