Jeremiah Burroughs was a puritan pastor, a member of the Westminster Assembly, and a prolific writer who worked for both the purity and unity of the church. He was considered the "prince of preachers" a couple hundred years before that other guy got the title. This is one post of a seven part distillation of the main "rules" from Burroughs' sermon on Phil 1:27 preached March 8, 1645. You can find the sermon in Gospel Conversation (Amazon, or WTS Books)
Seven Cautions for Christians #5: Uproot Your Secret Sins
"Only let your manner of life be worthy of the gospel of Christ" Phil 1:27
A life that honors that gospel requires you to uproot those hidden sins in your life before they ruin you. I have seen a number of men and women fall into serious sin and bring lasting devastation upon themselves and those close to them by not dealing seriously with the sin they kept secret.
What’s the reason that some who have been professors of religion a great while, and seemed to be very glorious in their profession, at length break out into some vile, scandalous sin? Surley the reason is that they have kept hidden some corruption within, and they have thought it a very horrible thing that this corruption in my heart and thought should ever break out.
If you take liberty to dally and play with this sin secretly in your thoughts and affections, it is just with God to leave you to shame yourself.
The man who pleases himself in any kind of secret sin will find it just with God to lead him forth with the worker of iniquity so as to lay his shame open and naked before all with whom he lives.
A life worthy of the gospel of Christ is not a sinless life, but a life that, though marred by sin, is also honest about its corruption, confesses it, and turns from it before it takes root and bears the fruit of death.