In Him you were also circumcised with the circumcision made without hands, by putting off the body of the sins of the flesh, by the circumcision of Christ…
~ Colossians 2:11 (NKJV)
Which [circumcision] is of the heart, in the spirit; every man… is uncircumcised in heart, until he is circumcised by Christ and his Spirit; which is done, when he is pricked to the heart, and thoroughly convinced of sin, and the exceeding sinfulness of it; when the callousness and hardness of his heart is taken off and removed, and the iniquity of it is laid open, the plague and corruption in it discerned, and all made naked and bare to the sinner’s view; when he is in pain on account of it, is broken and groans under a sense of it, and is filled with shame for it.
~ John Gill, Exposition of the Whole Bible
A Prayer Life 