'Steadfast' in the Bible

So all the men of Israel withdrew from following David and followed Sheba the son of Bichri; but the men of Judah remained steadfast to their king, from the Jordan even to Jerusalem.

“Then, indeed, you could lift up your face without moral defect,And you would be steadfast and not fear.

Create in me a clean heart, O God,And renew a steadfast spirit within me.

My heart is steadfast, O God, my heart is steadfast;I will sing, yes, I will sing praises!

For their heart was not steadfast toward Him,Nor were they faithful in His covenant.

A Song, a Psalm of David.My heart is steadfast, O God;I will sing, I will sing praises, even with my soul.

He will not fear evil tidings;His heart is steadfast, trusting in the Lord.

He who is steadfast in righteousness will attain to life,And he who pursues evil will bring about his own death.

“The steadfast of mind You will keep in perfect peace,Because he trusts in You.