"How shall I be sure of this?" said Zachariah to the Angel. "For I am an old man and my wife is advanced in years."

Now we are sure that you know all things, and have no need for any one to question you; by this we believe that you came forth from God."

"And as to his having raised him from among the dead, now no more to return to corruption, he has said this, "I will give thee the holy and sure blessings of David.

By no means! Be sure that God is ever true, though all mankind prove false. As it is written, That thou mayest be found just in thine argument, And gain thy cause when thou contendest.

Now in regard to food which has been offered to idols, we are sure of course that "we all have knowledge." But knowledge puffs up, while love builds up.

But of this be sure. In the last days grievous times will come.

you may be sure that such a man is perverted and sinning, and is self-condemned.

So, brothers, take diligent care to make your calling and election sure; for if you do this, you will never stumble.

And so we possess the word of prophecy made yet more sure. Unto this you do well to give heed as to a lamp shining in a dark place, till the day dawns and the morning star rises in your hearts.

then be sure that the Lord knows how to deliver the godly out of temptation, and to keep the wicked (who are even now enduring punishment) for the "Day of Judgment";