In case you're wondering, that is not the purpose of the Church (nor of Christians). The Bible teaches that
Christ also loved the church and gave Himself for her, that He might
sanctify and cleanse her with the washing of water by the word, that He might
present her to Himself a glorious church, not having spot or wrinkle or any such
thing, but that she should be holy and without blemish. (Eph 5:25-27)
So according to the Bible, its Christ who does the doing. Christ is the subject and we are the objects of His work. (Don't get me wrong, I'm not denying body ministry or that works must flow from our faith, just some traps we can fall into in our thinking about these things.)
On that note, I come (finally) to the subject of this post: The Gospel Mystery of Sanctification, by Walter Marshall. Marshall's point is just what I have been saying; we cannot do something to achieve holiness. Rather sanctification, like justification, is by grace.
Today, I think, most of us would prefer a How To book on holiness, or at least a 10-step guide. Preferably something we could start doing within a weekend. That is not at all what Marshall offers. This puritan gave no 5 point plan to achieve holiness before Christmas and no quick-fixes to besetting sins. Rather, Marshall turns our attention to the Gospel.
I think this Wordle of Marshall's book will give you good idea of his focus ...
Instead of pointing us to what we can do, Marshall points us to the Gospel, the Cross, Salvation, Grace, and Faith. Rather than encouraging us to look inward to our own works, Marshall encourages us to look outward to God's work in Christ.
Marshall brings us back to the Biblical truth that Christ is our sanctification (1 Cor 1:30). He reminds us of the truth of our tenet: 'Sanctification of the believer through the finished work of Christ.'
Since 1692 Marshall's book has been reminding Christians of the need for sanctification by faith. Even if his name is not well-known, and his book not atop the bestseller lists, throughout the years The Gospel Mystery of Sanctification has had a major impact. Such men as Andrew Murray, A.B. Simpson & William Cowper were all influenced by Marshall's book. John Murray went so far as to say that it was the most important book on sanctification that had ever been written.
Well, if Murray's right and it is the most important book on sanctification that has ever been written, I think that means it's worth a read.
The entire original text is available for free on PDF online from Monergism.com. The original text has also been republished by Reformation Heritage Books, or a modernized language edition has been published by Wipf and Stock.
If you really want to do something, read this book!