The psalm was written by David. It shows a man who was depressed because he felt that God had abandoned him. His enemies rule over him. It seems that God had forgotten him. David continues in his faith only by sheer will. This is really the purpose of this feeling of abandonment. God often hides himself to strengthen our faith.

The assumption to this is that one is not living in sin. When one sins, one rejects God and God respects that decision and God leaves. The darkness that follows that person is caused by that person's decision. The solution to this is to repent and beg for God's mercy.

When one enters spiritual darkness in a state of grace, this darkness is the most powerful lesson in faith. This is the stage where one literally, has to force one's self to believe in God. David experienced this. Verse 2 says, "How long shall I take counsel in my soul, having sorrow in my heart by day?" In his feeling of abandonment, David made a decision to trust in God. He asked God to open his eyes so that he may see him.

The mood turns in verse 5. David trusts in God's mercy and rejoices in his salvation. David will sing because God has dealt bountifully with him. This decision to trust in God is an act of will. It is not based on emotions. Even when he did not feel like it, when God seemed absent, David still trusted in the Lord's mercy. He looks forward to the saving power of God - and he acts as if this has happened. David sings and acts as if God had saved him. This act of will is faith - believing in the goodness of God.