"The pure love of our neighbour, springing from the love of God, thinketh no evil, believeth and hopeth all things. Now, this very temper, unsuspicious, ready to believe and hope the best of all men, may occasion our thinking some men better than they really are. Here then is a manifest mistake, accidentally flowing from pure love."
"For it has been allowed, that all who are in the body are liable to mistake; and that a mistake in judgment may sometimes occasion a mistake in practice; though great care is to be taken that no ill use be made of this concession. For instance: Even one that is perfected in love may mistake with regard to another person, and may think him, in a particular case, to be more or less faulty than he really is. And hence he may speak to him with more or less severity than the truth requires. And in this sense, (though that be not the primary meaning of St. James,) 'in many things we offend all.' This therefore is no proof at all, that the person so speaking is not perfect."
(quoted from Christian Perfection Q & A)
Here Wesley is saying that the man who is perfected in love, thinks no evil thoughts which is no other than sinless perfection. He has no lustful thoughts, he has no jealousy, he is fair with all men, but he cannot read the thoughts of other men. This is the area where a perfect man cannot be like God. Mistakes will frequecntly be made here, and it is often the case that the perfect man will err on the side of thinking the best of others. How much purer can a man be if he thinks no evil?
Many did not believe in perfection because they saw these mistakes in others and called them sins because they set the bar too high that man could not attain. If we did not make these errors we would be gods.
Calvinism sets the bar too high and says that everything that is not in accordance with Gods own behaviour is sin, but God made us to be dependent on Him for knowledge not to have divine knowledge ourselves and the growth in perfection is the gaining of this knowledge which will still be incomplete till we die. For this reason I do not think that the blood of Christ is needed because it is how God intended. He did not give Adam divine knowledge but intended him to look to God for it.
The blood is needed for cleansing the heart AND IN ORDER FOR IT TO REMAIN CLEAN. This is a day by day action and needed by the perfect man as his righteouness is not his own. The cleansing is not for the mind. The mind will show what is in the heart but the function of the brain is not to be the same as God`s. Obedience however, is. Perfect obedience to the light the Holy Spirit gives so that a man can do the complete will of the Father as did Jesus so that he walks as He walked and keep the moral law perfectly in love.