Bible Verses About Unbelief: Questioning the power of God

Then a lord on whose hand the king leaned answered the man of God, and said, Behold, if the LORD would make windows in heaven, might this thing be? And he said, Behold, thou shalt see it with thine eyes, but shalt not eat thereof.

Yea, they spake against God; they said, Can God furnish a table in the wilderness?

Behold, he smote the rock, that the waters gushed out, and the streams overflowed; can he give bread also? can he provide flesh for his people?