This passage describes two types of people: the pure and the defiled/unbelieving. The second group cannot become pure by doing good works, because they are “unfit for any good work.” Someone who is defiled cannot work himself out of defilement. The only way a defiled person can become pure is by being washed.
And such were some of you. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God. (1 Cor. 6:11 ESV)Do you want to be pure?