John Wesley, Anglican clergyman and movement founder and ultimately founder of the Methodist traditions, did teach that perfection was possible. He is the first person, I believe, to preach such a thing. It was controversial. However, we have his published writings on the topic. Indeed, we have a a series of writing, so we can see his thought. This is what he said.
You may obtain a copy of the official version on this link. It is widely available and still, occasionally, discussed. It is not believed by any Methodist church. It is not the same as any holiness group believes now. I submit to you, however, that given that John Wesley began the discussion about holiness in our culture and church history, that we should give him a good listen — at the very least. We will learn much. It is respecting the fathers of the faith, if nothing else.
I commend this to your study. I think it will both encourage us and correct us, if we study Wesley’s doctrine of perfection.