Continuing to believe firmly in Christ is spoken of as if it were holding something tightly. Alternate translation: "Continue to believe firmly" (See: [[rc://en/ta/man/jit/figs-metaphor]])
A crown was a wreath, originally of olive branches or laurel leaves, that was put on the head of a victorious athlete. Here "crown" stands for a reward. See how you translated "crown" in [Revelation 2:10](../02/10.md). (See: [[rc://en/ta/man/jit/figs-metaphor]])