The heart; the center, the core of your being, the real you.
With the heart man believes; ( God gave you the faith to believe that Jesus is Lord, now the measure of faith can develop and grow to believe that you are made righteous by his righteousness.) Once you believe this, the prayers of the righteous makes much power available.
James 5:16-18
The Prayer of Faith
…16 Therefore confess your sins to each other and pray for each other so that you may be healed. The prayer of a righteous man has great power to prevail. 17 Elijah was a man just like us.He prayed earnestly that it would notrain, and it did not rain on the land for three and a half years. 18 Again he prayed, and the heavens gave rain, and the earth yielded its crops
Come on, get up God has so much for you to do. (That’s a word some.)
Romans 10:10
King James Version
For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation.