(idiomatic) Events and outcomes cannot be known beforehand.

(informal) Said ironically to scold somebody who is staring at the speaker.

(archaic) One should take immediate advantage of an opportunity that may not be available later.

(idiomatic) A response to taunting proclaiming the speaker's indifference.

Alternative form of if you lie down with dogs, you get up with fleas

Belief in oneself (read sometimes as belief in God) can help one overcome any hurdle in life's path.

Alternative form of where there is a will there is a way

Ellipsis of where there is a will there is a way.

If someone wants or wills something strongly enough, a way can be found to make it happen.

Used to propose marriage to someone