Another guarantee of our inheritance is our persevering faith. Peter said we are protected by God’s power through faith (1 Pet. 1:5). Faith is God’s gift to us; we don’t generate it on our own (Eph. 2:8-9; Phil. 1:29). Faith is aroused by grace, upheld by grace, and energized by grace. Grace reaches into the soul of the believer, generating and maintaining faith. By God’s grace alone we trust Christ, and by grace we continue to believe.
John MacArthur