The heart will lie to us. The Bible says that the heart is wicked. We can’t always count on it to do the right thing. At the same time, the Bible tells us that everything we say flows from our heart. It is impossible for us to rely on our hearts to do the right thing, unless they are pure. In order to know that, we must ask God to search our hearts, with the strongest possible searchlight. He alone can see the truth in our hearts. He can show us any evil leanings or hurtful intents. This is a task that we are simply not up to. Only God can purify our hearts.
And we pray:
Dear Lord, search my heart. Cast out any impurities You find there. Any wickedness or deceit. Any desire to hurt others. Make my heart whole and pure. Help me hold only L/love in my heart all of my days. Amen.