From John Wesley's Journal

It is always worth remembering just how reliant we are upon God's grace.  We sometimes want to make claims about our achievements, but then do well to remember how we need God's help to get there.  The apostle Paul was clear on that realisation.  He wrote to the Philippians: "If anyone else has reason to be confident in the flesh, I have more:  circumcised on the eighth day, a member of the people of Israel, of the tribe of Benjamin, a Hebrew born of Hebrews; as to the law, a Pharisee;  as to zeal, a persecutor of the church; as to righteousness under the law, blameless.  Yet whatever gains I had, these I have come to regard as loss because of Christ.    (Philippians 3:4-7)

In a similar way John Wesley reflects in his journal:

Sunday 29 January 1738

"Are they read in philosophy?  So was I.  In ancient or modern tongues?  So was I also.  Are they versed in your science of divinity?  I too have studied it many years.  Can they talk fluently upon spiritual things?  The very same could I do.  Are they plenteous in alms?  Behold, I gave all my goods to feed the poor.  Do they give of their labour as well as of their substance?  I have laboured more abundantly than they all.  Are they willing to suffer for their brethren?  I have thrown up my friends, reputation, ease, country; I have put my life in my hand, wandering into strange lands; I have given my body to be devoured by the deep, parched up with heat, consumed by toil and weariness, or whatever God should please to bring upon me.  But does all this - be it more or less, it matters not - make me acceptable to God?  Does all I ever did or can know, say, give, do, or suffer, justify me in his sight?  Yea, or the constant use of all the means of grace?  ....  Does all this give me a claim to the holy, heavenly, divine character of a Christian?  By no means. "

We should do what we can, but we must not claim that we can do it on our own.