"Teach me your way, O LORD, and I will walk in your truth; give me an undivided heart, that I may fear your name." -- Psalm 86:11
Some of the most notorious criminals in history have been "double agent" spies. They spy for two countries but they are loyal to neither one. These people play two ends to the middle and ultimately do more harm than good. They have divided hearts.
The psalmist asked to be taught the ways of the Lord so he would walk in God's truth. Yet, he knew that knowledge is only as good as the hearts devotion. As a spy has more than knowledge than most, if the heart is divided, the value of that knowledge is lost. Therefore, psalmist prayed for an "undivided heart".
To whom do you devote your heart my friend? Jesus taught that you can't serve two masters (Matthew 6:24) and James noted that your prayers should be made without doubt (James 1:6). As much as you desire to walk in the ways of the Lord, don't forget your heart, for it's the wellspring of life (Proverbs 4:23).