Psalm 40:11 says, "Do not withhold your mercy from me, O LORD; may your Love and your Truth always protect me."

I read this last week and I used it as my prayer for that day and the days following.  Here is what I got out of what David was saying:

• He asked God to "not withhold your mercy from me".  Basically he is saying that he knows he is a sinful guy and that he has messed up a bunch.  So as he is trying to do what is right he is asking for God to be merciful and gracious to him.
• He says, "may your love...always protect me."  I believe love is personal.  Relationships in general are messed up as they can be very self-centered and conditional; a sort of a "what have you done for me lately" mindset.  But God gives unconditional love and it will always cover and protect us no matter what situation we are in.  His love is greater than all things and it will protect us through the great times and the bad as long as we allow ourselves to feel the love.
• Finally he says, "may your truth always protect me."  The fact is people will always have their own version of the truth as truth can sometimes be how we perceive things to be (whether we are right or wrong).  But REAL truth rests in the Lord.  After all He did say, "I am the way, the TRUTH and the life".  He is the ultimate truth and understanding.