'Have Faith' in the Bible

And Jesus said to them, 'Through your want of faith; for verily I say to you, if ye may have faith as a grain of mustard, ye shall say to this mount, Remove hence to yonder place, and it shall remove, and nothing shall be impossible to you,

And Jesus answering said to them, 'Verily I say to you, If ye may have faith, and may not doubt, not only this of the fig-tree shall ye do, but even if to this mount ye may say, Be lifted up and be cast into the sea, it shall come to pass;