Note 8 at 1 Cor. 6:12: We are saved by grace, not by our actions (see ref. t at v. 11, p. 886). Therefore, a Christian can technically do anything and retain his salvation, but God forbid that any Christian would think that way (1 Jn. 3:3). A Christian has a new nature that doesn't want to sin and he is also aware that sin gives Satan access to us to cause misery and pain in this life (see note 2 at Rom. 6:2, p. 776).

This is the point that Paul is making. He was free in Christ to do whatever he wanted to do, but he didn't want to do anything that would bring him under the oppressive power of Satan. A person who has truly been born again gets his "want to" changed.