'Faithful' in the Bible

On getting there he was delighted to see the grace which God had bestowed; and he encouraged them all to remain, with fixed resolve, faithful to the Lord.

But even the sacrifice of my life I count as nothing, if only I may perfect my earthly course, and be faithful to the duty which the Lord Jesus has entrusted to me of proclaiming, as of supreme importance, the Good News of God's grace.

The following night the Lord came and stood at Paul's side, and said, "Be of good courage, for as you have borne faithful witness about me in Jerusalem, so you must also bear witness in Rome."