This argument is directed to people who believe in One Justification Through Faith Alone, i.e. the JBFA people. This ploy is also commonly levied to people who are shaky in their confidence with UOJ and to keep these people in a coral, they throw a guilt trip saying to them - if they abandon UOJ then you must believe in your own faith.
This is also called the fallacy of post hoc ergo propter hoc, i.e., because of this, then this follows, and so on. People not accustomed to spotting fallacies are prone to slip and go along this UOJ fallacy.
Let us examine this conclusion a bit - it says if you do not believe in UOJ then you must believe in faith in your faith, or you will then have faith in your faith.
Now no where in the Bible does it teach that there is a thing called faith in your faith. Jesus often tells people who believed in him that their faith has saved them. For example Lk 7:50. Yet it is Jesus who says this about these people's faith. No where do we see anyone who believes in Jesus commend himself/herself's faith. The very nature of the faith taught in the Bible is that it's object is not directed to itself but away from it, to Christ's person as Lord and his work of atonement. By the Bible's definition, saving faith has Christ's person and work as its object.
Consider now the published teachings of UOJ teachers we have encountered in this blog. We have clear evidence (if you search here) that for the UOJer, the object of faith is directed at that so called "justification" that has happened on all people 2000 years ago when either Jesus breathed his last or when he was resurrected from the dead (which one event specifically caused our "justification", no one knows).
Consider further what UOJers teach about people who do not believe this general or objective justification. They teach that if you reject this general objective justification you are not subjectively justified and hence, one can say you are "unjustified". It is somewhat laughable and hypocritical that they throw the "faith in your faith" on to JBFAers when in fact the same is true for them. For is it not reasonable to say the same thing applies to UOJ teaching? For if you want to be justified, you must believe that you already have been and if you don't then you are not. This too results in faith in faith and in fact far more so and worst because the object is not Christ and his work. Let us not go very far, let us simply quote their famous saint C. F. W. Walther
"For God has already forgiven you your sins 1800 years ago when He in Christ absolved all men by raising Him after He first had gone into bitter death for them. Only one thing remains on your part so that you also possess the gift. This one thing is—faith. And this brings me to the second part of today's Easter message, in which I now would show you that every man who wants to be saved must accept by faith the general absolution, pronounced 1800 years ago, as an absolution spoken individually to him."The emphasis there is mine. Yet note what Walther said - one thing remains ON YOUR PART... and EVERY MAN WHO WANTS TO BE SAVED MUST ACCEPT. It is indeed amazingly weird to think that the UOJer's faith can not result in faith in that faith, as if it could never happen to a UOJer.
C. F. W. Walther, The Word of His Grace, Sermon Selections, "Christ's Resurrection—The World's Absolution" Lake Mills: Graphic Publishing Company, 1978, p. 233. Mark 16:1-8.
There is one thing I want to ask a UOJer - are you sure that you believe in that general absolution pronounced 2000 years ago? For if you are not, as per Walther's teaching you are not saved.
On the other hand, the faith spoken of by JBFA teaching is a faith that can not boast and can not look at no other object except Christ's work and person. It locks the believer into the proper place to rest one's faith and hence, its very nature can not look at itself nor somewhere else.
2 Timothy 1:12
New King James Version (NKJV)
12 For this reason I also suffer these things; nevertheless I am not ashamed, for I know whom I have believed and am persuaded that He is able to keep what I have committed to Him until that Day.