The means of the accomplishment of sin in the life of the believer, (or the fulfillment of any given sin) is for the sinners recognition of sins necessity in that it brings the Christian believer to repentance and therein remembrance of their continual great need of the grace of the only one who can help them and is once again embarked upon; that being specifically, the grace and mercy of the Lord Jesus Christ!
This is not to say that sin is to abound so that this grace may be experienced more (Ref. Romans 6:1), or that it should increase. Rather, it is to say that the sinner, (being the believer), must again give all glory to Christ and thank Him for His power given them to overcome sin, and the deliverance from sin over and over again. This blessed deliverance is done only by way of the Sovereignty of God in the work of the Lord Jesus Christ by the power of the Holy Spirit.
This may seem as if I am rewarding sin as it accomplishes its goal. This thought isn’t what I am referring to at all. The goal of sin ultimately, is to destroy. It’s goal therefore is the utter destruction of a person, or more specifically, the sinner. However, sin in the life of the believer, (if the reader will think this out with me) is a help to the Christian more than it is a harm; which is only unto their sanctification.
I am desiring to bring an understanding of sanctification in the life of the Christian, and the duty of sin as being a help to them. This brings an oxymoronic rendering due to the fact that sin is rightly understood as a destroyer more than it is a help. When sin bites, be it ones attitude, prayerlessness, or to even greater sin that has dreadful consequences, and thereby having found themselves in the miry clay of dispondance once again, what does the Chrsitian conclude as to why they are there?
My conclusion to this very short summary would be a desire to leave it open with this question for the cause of the believer being provoked to thinking about how they respond to daily sin in their life.
I would also refer you to chapter 5, section 5 of the 2nd London Baptist Confession of Faith on the Providence of God for the lives of both the believer and the non-believer. If you do not have a copy of the 2nd LBCF, Google will help you find it, or let me know and I can get you one! Reference also Romans Chapters 6-7.
Soli Deo Gloria!