John Wesley, the co-founder of the Methodist Church, believed in Christian Perfectionism. Consider these quotes from him:

But whom then do you mean by "one that is perfect?" We mean one in whom is "the mind which was in Christ," and who so "walketh as Christ also walked;" a man "that hath clean hands and a pure heart," or that is "cleansed from all filthiness of flesh and spirit;" one in whom is "no occasion of stumbling," and who, accordingly, "does not commit sin." To declare this a little more particularly: We understand by that scriptural expression, "a perfect man," one in whom God hath fulfilled his faithful word, "From all your filthiness and from all your idols I will cleanse you: I will also save you from all your uncleannesses." We understand hereby, one whom God lath "sanctified throughout in body, soul, and spirit;" one who "walketh in the light as He is in the light, in whom is no darkness at all; the blood of Jesus Christ his Son having cleansed him from all sin."

This man can now testify to all mankind, "I am crucified with Christ: Nevertheless I live; yet not I, but Christ liveth in me." He is "holy as God who called" him "is holy," both in heart and "in all manner of conversation." He "loveth the Lord his God with all his heart," and serveth him "with all his strength." He "loveth his neighbour," every man, "as himself;" yea, "as Christ loveth us;" them, in particular, that "despitefully use him and persecute him, because they know not the Son, neither the Father." Indeed his soul is all love, filled with "bowels of mercies, kindness, meekness, gentleness, longsuffering." And his life agreeth thereto, full of "the work of faith, the patience of hope, the labour of love." "And whatsoever" he "doeth either in word or deed," he "doeth it all in the name," in the love and power, "of the Lord Jesus." In a word, he doeth "the will of God on earth, as it is done in heaven."

This it is to be a perfect man, to be "sanctified throughout;" even "to have a heart so all-flaming with the love of God," (to use Archbishop Usher"s words,) "as continually to offer up every thought, word, and work, as a spiritual sacrifice, acceptable to God through Christ." In every thought of our hearts, in every word of our tongues, in every work of our hands, to "show forth his praise, who hath called us out of darkness into his marvellous light." O that both we, and all who seek the Lord Jesus in sincerity, may thus "be made perfect in one!"

This should provide an adequate sense of Wesley's view. He believed that a Christian can be sinless, like Christ, in this life. I've highlighted certain citations that even come from our present reading in 1 John. Yet, this view stands contrary to the clear teaching of Scripture. Consider 1 John 1:8-10,

If we claim to be without sin, we deceive ourselves and the truth is not in us. If we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness. If we claim we have not sinned, we make him out to be a liar and his word is not in us.

Wesley would agree with the latter, namely, that we cannot claim that "we have not sinned"; however, he must also contend with John's former point, namely, "if we (presently) claim to be without sin..." John says that those who do so are self-deceived and devoid of truth.

What is more, Paul's testimony of his unceasing struggle with sin stand against Wesley's thesis:

For I know that good itself does not dwell in me, that is, in my sinful nature.  For I have the desire to do what is good, but I cannot carry it out. For I do not do the good I want to do, but the evil I do not want to do—this I keep on doing. Now if I do what I do not want to do, it is no longer I who do it, but it is sin living in me that does it. So I find this law at work: Although I want to do good, evil is right there with me. For in my inner being I delight in God’s law; but I see another law at work in me, waging war against the law of my mind and making me a prisoner of the law of sin at work within me. What a wretched man I am! Who will rescue me from this body that is subject to death? Thanks be to God, who delivers me through Jesus Christ our Lord! So then, I myself in my mind am a slave to God’s law, but in my sinful naturea slave to the law of sin (Romans 7:18-25).

Some people have tried to claim that Paul was talking about his pre-conversion past, but if this were the case, he would speak in the past tense and not in the present. He does not say, "What a wretched man I was!" No, he says, "What a wreteched man I am!" And even after speaking of deliverance in Christ, he reiterates the continuing struggle with the declaration, "I myself in my mind am a slave to God's law, but in my sinful nature a slave to the law of sin."

How then does Wesley come to his conclusion? I believe that he has taken certain absolute statements in Scripture, which speak of our position in Christ, and understood them as the practical experience for the Christian. In doing so, he has to try to explain away passages like the ones I presented above. Of course, he would say that I am explaining away the absolute passages, like those that teach that those born of Christ do not sin. My response would be, then, that by such a standard I know of no one who is a Christian, and I daresay, except in his imagination, Wesley did not know any perfect people in his day either.

But where does such a belief come from? We know that Wesley believed in salvation by "free will," which, as today, was in vogue in eighteenth century England. As such, he had a high view of humanity and a lesser view of God. His counterpart, George Whitfield, held the minority view that salvation is by God's sovereign election. It is interesting to me that those we hold in highest biblical and theological esteem (e.g. St. Augustine, Martin Luther, John Calvin, Jonathan Edwards, Charles Spurgeon, George Whitfield, etc.) all held to salvation by God's sovereign election, yet they often represented the minority voice in their generation. The majority embraced salvation by free-will.

To me a belief in Christian perfectionism arises naturally out of a high view of ourselves, even of humanity in general. For those that hold to God's sovereign election recognize the depth of human depravity, even our inability, not only to do what is right ("good works") but even to choose what is right ("saving faith").

So, for those that believe in a free-will-based salvation, one error breeds another. Christian perfection is unbiblical and so is salvation by free-will. This should serve as a warning to those that tenaciously hold on to such error in thinking.