'Have Faith' in the Bible

And Jesus said unto them, Because of your unbelief: for verily I say unto you, If ye have faith as a grain of mustard seed, ye shall say unto this mountain, Remove hence to yonder place; and it shall remove; and nothing shall be impossible unto you.

But whoever is a cause of trouble to one of these little ones who have faith in me, it would be better for him to have a great stone fixed to his neck, and to come to his end in the deep sea.

Jesus answered and said unto them, Verily I say unto you, If ye have faith, and doubt not, ye shall not only do this which is done to the fig tree, but also if ye shall say unto this mountain, Be thou removed, and be thou cast into the sea; it shall be done.

and everything, whatever it be, that you ask for in your prayers, if you have faith, you shall obtain."

The baptism of John, where did it come from? from heaven or from men? And they were reasoning among themselves, saying, If we say, From heaven; he will say to us, Why then did you not have faith in him?

For John came to you in the way of righteousness, and you had no faith in him, but the tax-farmers and the loose women had faith in him: and you, when you saw it, did not even have regret for your sins, so as to have faith in him.

A saviour of others, he has no salvation for himself. If he is the King of Israel, let him now come down from the cross, and we will have faith in him.