Chapter 7 of John Owen’s Of the Mortification of Sin in Believers

There will be no mortification unless a man be a believer. Unless a man be a believer – that is, one that is truly ingrafted into Christ – he can never mortify any one sin; I do not say, unless he know himself to be so, but unless indeed he be so (79).

A man may easier see without eyes, speak without a tongue, than truly mortify one sin without the Spirit (80).

This is that I aim at: unless a man be regenerate, unless he be a believer, all attempts that he can make for mortification, be they never so specious and promising – all means he can use, let him follow them with never so much diligence, earnestness, watchfulness, and intention of mind and spirit – are to no purpose (81).

Be sure to get an interest in Christ – if you intend to mortify any sin without, it will never be done (83).