Ah, but who is it that opens the "door"? Acts of the Apostles 16:14 And a certain woman named Lydia, a seller of purple, of the city of Thyatira, which worshipped God, heard us: whose heart the Lord opened, that she attended unto the things which were spoken of Paul.
(emphasis mine)
And, who gives a new heart? Ezekiel 36:26-27 A new heart also will I give you, and a new spirit will I put within you: and I will take away the stony heart out of your flesh, and I will give you an heart of flesh. And I will put my spirit within you, and cause you to walk in my statutes, and ye shall keep my judgments, and do them.
Notice, God gives a new heart, God puts a new spirit within, God takes away the stony heart, God gives a heart of flesh, God puts His spirit within, God causes to walk in His statues and keep His judgments.