Charles H. Spurgeon on Psalms 138:8

The grace of God makes a man thoughtful, and leads him to concern about himself, his life, his future, and the completeness of the work of grace. This might lead us to sadness and despair, but the Lord worketh in us for other ends.

1. He fills us with assurance. a) That the Lord will work for us. b) That he will complete his work. c) That he will do this in providence; if it be properly a concern of ours. d) That he will do this within us. Our graces shall grow. Our soul shall become Christly. Our whole nature perfect. e) That he will do this with our work for him.

2. He gives us rest in his mercy. a) Thou wilt forgive my sins. b) Thou wilt bear with my nature. c) Thou wilt support me in suffering. d) Thou wilt supply me in need. e) Thou wilt succour me in death.

3. He puts prayer into our hearts. a) That he will not forsake me. b) That he will not leave his own work in me undone. c) Nor his work by me unfinished. Why did he begin? Why carry so far? Why not complete?