'Sure' in the Bible

And their eyes were opened. Then Jesus warned them sternly, “Be sure that no one finds out!”

I am sure of this, that He who started a good work in you will carry it on to completion until the day of Christ Jesus.

To be sure, some preach Christ out of envy and strife, but others out of good will.

We have this hope as an anchor for our lives, safe and secure. It enters the inner sanctuary behind the curtain.

This is how we are sure that we have come to know Him: by keeping His commands.