Here is the new desires we are given at our salvation. Before we were saved we only had desires please ourselves. We made choices that were according to how it made us look to other people and made us feel good about ourselves.
Perfectionism is when we think like a pagan. We think that our choices are purely rational. We think that we can reason through the command to obey and obey by choosing to obey in our own power. When we have this view of choosing we set up our own standards so that we can rationally prove that we obey.
Edwards is saying that when we were pagans we sinned because we were sinners. In other words we desired to sin more than we desired to obey. We choose one thing over another based apoun how it pleased us. We loved sin and the pleasure and so that love of sin grew as we sinned. In the mean time we reasoned that we did more good than sin to protected our pleasure in that sin.So sin became a way of life.
When we were given new desires at salvation it reversed our desires. Now we love God because we are regenerated and we have the Holy Spirit. We are made new. We desire God. Now our desires for Gods glory grow as we desire more of Him. The longer we live the more we learn His will the more we desire to love Him the greater the desires become. On the reverse we hate sin. We feel bad about displeasing Him. We react against sin by mourning over sin. This desire grows as our desires to love God grow.
A perfectionist does not consider that God changes the inside before the outside is changed. He thinks that he can will a change without the proper desires to change. He leaves out grace by self will. Grace is the power to change the heart and thus changes the desires. All inward change comes from grace. God is the only one who can change the heart. He does it by grace.
So that the spiritual appetite after holiness, and an increase of holy affections is much more lively and keen in those that are eminent in holiness, than others, and more when grace and holy affections are in their most lively exercise, than at other times. It is as much the nature of one that is spiritually new born, to thirst after growth in holiness, as it is the nature of a new born babe to thirst after the mother's breast; who has the sharpest appetite, when best in health. 1 Pet. 2:2, 3, \"As new born babes, desire the sincere milk of the word, that ye may grow thereby: if so be ye have tasted that the Lord is gracious.\" The most that the saints have in this world, is but a taste, a prelibation of that future glory which is their proper fullness; it is only an earnest of their future inheritance in their hearts, 2 Cor. 1:22, and 5:5, and Eph. 1:14.-Edwards As our desires grow in us through the means of grace we begin to be passionate about Christ. As the passion increases so the holiness increases. It is through grace an by love in relationship that we are made holy.