The only way to get it out is open heart surgery. Painful. But God only wounds us so that he can heal us. He only cuts so that he can heal and make us whole. In the same way that doctors don't demand to cut out veins or whatever it is they do in people, perhaps God is the same way. Doctors don't demand you come to them, you come to them and demand they take cancer out. And, you expect it to not come back, with the doctor's assurance, of course.
So, why do we let sin reign in our mortal bodies? good question...