'Mighty' in the Bible

And when the sabbath day was come, he began to teach in the synagogue: and many hearing him were astonished, saying, From whence hath this man these things? and what wisdom is this which is given unto him, that even such mighty works are wrought by his hands?

And he could there do no mighty work, save that he laid his hands upon a few sick folk, and healed them.

And king Herod heard of him; (for his name was spread abroad:) and he said, That John the Baptist was risen from the dead, and therefore mighty works do shew forth themselves in him.