Defending Justification by Faith Alone

In my study of covenant keepers/breakers I ran across a sermon by John Piper where he said the following:

Covenant Warnings
What we need to see here is sobering. The covenant warning here is that the path of sin can lead to death without a covering for sin. In other words, it leads to destruction and eternal lostness in hell. Verse 20: He who turns a sinner from the error of his way will save his soul from death, and will cover a multitude of sins.

Utterly Crucial to See
If the sinner turns back from his slide into sin, he will escape death and will be in a relationship with Christ that covers all his sins. But if he does not turn back, then he will die, and his sins will not be covered. He will perish forever.

This is utterly crucial to see. The New Testament writers do not assume that everyone in the church is necessarily going to persevere to the end and be saved. They treat people who have made a profession of faith as true members of the covenant community, giving them the benefit of the doubt. James calls them all "brothers" in verse 19. "My brethren, if any among you strays from the truth . . . "

ENTIRE SERMON:
http://www.desiringgod.org/resource-library/sermons/preserving-the-covenant-community-in-spite-of-sickness-and-sin

My problem is not with his view of professing believers who are not saved being in the church, but his apparent works salvation in the portion underlined. He is talking about a professing believer who is not saved and will perish forever unless he “turns back from his slide into sin”. He is not talking about a TRUE believer falling into sin for a season. He is either referring to an unbeliever or losing salvation (unthinkable). His message is that a hypocrite will be saved by “turning back from his slide into sin”. This will give him "a relationship with Jesus."


While I am sure Piper affirms justificatin by faith alone, this is not the first time I have noticed a DEFACTO works component in his sermons. I just believe this situation is covered concisely and beautifully by Paul in Eph. 2:8-10. Faith produces the relationship with Jesus and fruit is the inevitable result, rather than making the fruit the basis for the saving relationship as is the case in this statement by Piper.