#but they do have a shared theological heritage with presbyterians and congregationalists and such

[ainsi-soit-il]

I’m actually really interested in learning what your denomination thinks about sanctification if you feel up to a long post about it? (Ulterior motive: I wanna go through and find the parts where Catholics disagree/define sanctification differently.)

Sorry for taking so long to reply! Thank you for your patience, and thanks for asking!

To some degree, Wesleyan theology does treat salvation as something that's immediate, with John Wesley writing at one point, "It [salvation] is not something at a distance, It is a present thing, a blessing which through the free mercy of God you are now in possession of."

But Wesleyan theology (and I'd argue Scripture itself too) also holds that even then, justification is just the beginning, and we are continually being perfected by God's grace.

This is how John Wesley put it in The Scripture Way of Salvation:

From the time of our being "born again," the gradual work of sanctification takes place. We are enabled by the Spirit to "mortify the deeds of the body" (Romans 8:11, 13) and of our evil nature, and as we are more and more dead to sin, we are more and more alive to God.

In other words, God's grace and the power of the Holy Spirit slowly transform our deeds and desires, so that we become more and more like Christ.

In the Wesleyan understanding of sanctification, sanctification takes place as believers grow to love God more. St. John's language of "being perfected in love" in 1 John 4.

This is how love is made perfect in us, enabling us to have confidence on the Day of Judgment, because even in this world we have become like him. In love there is no fear; indeed, perfect love casts out fear, because fear has to do with punishment, and whoever fears has not yet achieved perfection in love. Therefore, we love because he first loved us. (NCB, v. 17-19)

Effectively, as we grow to know and love God more, we find our desires transformed. Sin becomes less and less attractive. We no longer want the same things that we wanted before, and instead our desires are increasingly aligned with the will of God.

And that is effectively what Christian perfection (or "being perfected in love", or "entire sanctification"... Wesley didn't tend to stick with one term for things) means. It's the point where there's no more room in one's heart for sinful desires, because one is that full of the love of God. Irish theologian William J. Abraham described it as, "the point in [someone's] relationship with God where disobedience [i]s no longer a live option for them."

It's worth pointing out that this perfection is not absolute. We're finite creatures, after all. We get into misunderstandings, lack knowledge, etc. and so as a result, we'll still end up sinning. But Wesleyan theology places a distinction between these sorts of sins and the intentionally-done sort of sins we are freed from when we are perfected in love. (From what I understand, Catholic theology has a similar distinction between venial sins and mortal sins.)

This is distinct from Presbyterians and most Baptists (both within the same umbrella of Protestant theology), where entire sanctification is something we never quite attain in life. Even so, a Baptist or Presbyterian might argue, we still are called to keep "running the race", to use St. Paul's analogy.

Hope this helps!