Psalm 31:24 Be of good courage, And He shall strengthen your heart, All you who hope in the Lord.

Good courage fastens or holds fast to the Word of the Lord.  Everything is pinned on that which one is standing for.  In that condition courage is strengthened to establish our inner resolve.

Who is this promise decreed to?  To those “who hope in the Lord”, those who have placed their expectation in and on Him.  Knowing those determinations empowers us to be courageous.