Search me, O God, and know my heart!
Try me and know my thoughts!
And see if there be any grievous way in me,
and lead me in the way everlasting!
Psalm 139:23-24 (esv)
Today as you fast and pray, ask God to reveal any sin in your life. Scripture says God not only knows our hearts, he searches them. To me that means he is continually examining our hearts. As a Christian, the Holy Spirit lives within us, we are a temple of the Holy Spirit according to Paul in 1 Corinthians 6:19. The idea that God is continually searching our hearts may sound ominous, or intrusive, or intimidating. However, there are good reasons for God to be searching our hearts.
To not be deceived by sin - The psalmist states in Psalm 139 for God to search his heart, to try him, and know his thoughts. The reason for this searching out is to find any grievous or wicked way in him. Simply because he desires to be led by God in His ways. The psalmist doesn't want the deception of sin or misaligned thoughts to lead him away from the path God has for him.
To intercede for us - Romans 8:26-27 says, "Likewise the Spirit helps us in our weakness. For we do not know what to pray for as we ought, but the Spirit himself intercedes for us with groanings too deep for words. And he who searches hearts knows what is the mind of the Spirit, because the Spirit intercedes for the saints according to the will of God." (esv) As God searches our hearts, knowing we are week and don't always know what we should pray, His Holy Spirit intercedes for us and prays to God on our behalf. The great thing about that is the Holy Spirit shares the mind of God and His intercession is in line with the will of God. So the Holy Spirit, in a way unknown to us, is seeking God's will for us.
To show himself strong through us - The first part of 2 Chronicles 16:9 says, "For the eyes of the Lord run to and fro throughout the whole earth, to give strong support to those whose heart is blameless toward him." This is one of my favorite verses. God is actively searching hearts, looking for those hearts that are wholehearted toward Him. God does this so that he might lend His strength, His support, to our lives lived in subjection to Him.
Today, ask God to search your heart. Ask him to keep you from deceitfulness of sin. Ask Him to intercede for you, that you might fulfill His will for you. Ask Him to show himself strong through your obedience to Him. Ask Him to sustain your fast and strengthen your heart as you spend time in his presence.