'Continue' in the Bible

What shall we say then? Are we to continue in sin so that grace may increase?

Behold then the kindness and severity of God; to those who fell, severity, but to you, God’s kindness, if you continue in His kindness; otherwise you also will be cut off.

And they also, if they do not continue in their unbelief, will be grafted in, for God is able to graft them in again.