The proof is there. How many fulfilled prophecies does it take? How many witnesses of miracles does it take?
It's just like the pictures of the men on the moon. The truly determined will find a way to disbelieve them, to consider them forgeries or trickery.
Same thing with the proofs of God. No other God has the kind of witnesses to miracles and prophecies that God has. But you don't want to believe them. My guess is that even if God did big miracles right in front of your eyes, you wouldn't believe it. You'd chuckle and say, "how did they do that?".
If you want a fairly good partial enumeration of the many proofs out there. Pick up Josh McDowell's "Evidence that demands a verdict". Or "Evidence that demands a verdict II".
Don't bother, most atheists would not deign to soil them selves with such an "erudite" suggestion.