What does Psalm 27:9 mean?

When God "hides His face" from us, it means He is displeased. The imagery is of a parent turning to look somewhere else when a child is disrespectful or rude. David did not want the Lord to be displeased with him. He knew he was a sinner who did not deserve the Lord's presence and blessings. Because of his sinful condition, he knew he deserved for the Lord to reject him in anger. Although the Lord had anointed David to be king over all Israel, David humbly referred to himself as the Lord's servant.

Psalm 51:17 assures us that the sacrifices the Lord accepts are a broken spirit and a broken and contrite heart. Faced with overwhelming opposition, David's spirit was broken before the Lord and his heart was broken and contrite. He recalled that God had helped in the past and urged Him not to abandon him now. He addressed his prayer to the God of his salvation. He recognized that only God could deliver him in his time of crisis.

This verse shows both sides of David's faith when compared to Psalm 27:3. David "knows" that God is with him, and yet he still experiences human fears and anxieties. His response to those emotions is not panic, or despair, but a trusting appeal to the Lord.