Security

 Preserve me, O God, for in you I take refuge. I say to the Lord, "You are my Lord; I have no good apart from you."

Psalm 16:1-2 (ESV)
 
I have no good apart from God? Is this correct? Yes. David continues.
 
"I bless the Lord who gives me counsel; in the night also my heart instructs me. I have set the Lord always before me; because he is at my right hand, I shall not be shaken. Therefore my heart is glad, and my whole being rejoices; my flesh also dwells secure."
Psalm 16:7-9 (ESV)
 
I do not think you can ever get to the point where you always set the Lord before you until you realize that you have no good in yourself apart from God. To put any confidence in this flesh is a waste of time and will prove futile.
 
It is not our flesh that we need to make glad; it is our heart, and our heart can only be glad when it is right with God. When our heart is glad, our flesh "feels" secure. Our only security comes from God.