'Steadfast' in the Bible

Therefore, my dear brothers, be steadfast, unmovable, always excelling in the work of the Lord, because you know that the work that you do for the Lord isn't wasted.

However, you must remain firmly established and steadfast in the faith, without being moved from the hope of the gospel that you heard, which has been proclaimed to every creature under heaven and of which I, Paul, have become a servant.

"Twas not for deeds that we had done, but by his steadfast love alone, he saved us through a second birth, renewed us by the Spirit's work,