'Firm' in the Bible

But the man who is firm in his commitment, and is under no necessity but has control over his will, and has decided in his own mind to keep his own virgin, does well.

So then, dear brothers and sisters, be firm. Do not be moved! Always be outstanding in the work of the Lord, knowing that your labor is not in vain in the Lord.

Stay alert, stand firm in the faith, show courage, be strong.