I say, then, mortification is not the present business of unregenerate men. God calls them not to it as yet; conversion is their work,—the conversion of the whole soul,—not the mortification of this or that particular lust. You would laugh at a man that you should see setting up a great fabric, and never take any care for a foundation; especially if you should see him so foolish as that, having a thousand experiences that what he built one day fell down another, he would yet continue in the same course. So it is with convinced persons; though they plainly see, that what ground they get against sin one day they lose another, yet they will go on in the same road still, without inquiring where the destructive flaw in their progress lies.
When the Jews, upon the conviction of their sin, were cut to the heart, Acts 2:37, and cried out, “What shall we do?” what doth Peter direct them to do? Does he bid them go and mortify their pride, wrath, malice, cruelty, and the like? No; he knew that was not their present work, but he calls them to conversion and faith in Christ in general, verse 38. Let the soul be first thoroughly converted, and then, “looking on Him whom they had pierced,” humiliation and mortification will ensue.
– John Owen –
from The Mortification of Sin in Believers, volume 6 of Works, page 35