The heavenly Father is talking to Jeremiah in chapter 17: 9, 10 when He says: "The heart is deceitful above all things, and desperately wicked; who can know it? I, the LORD, search the heart, I test the mind, even to give every man according to his ways, according to the fruit of his doings."
Reaching our full potential begins with a clean heart—one that loves the Lord and desires to obey Him. However, each of us was born with a nature bent away from God. Salvation changed our hearts and lives. Jesus’ death on the cross paid the penalty for our sin and broke its power over us. By receiving Christ as Savior, we each became a new creation—with a heart sensitive to the Holy Spirit’s leading and a mind that strongly desires to know the Father better.