In English, user 'for' can quite validly and indisputably mean "in order to get" or "because of," but not both at the same time. You and Truther and others have... chosen the wrong one. It's a simple misunderstanding, but a misunderstanding it is, on your part.
Now, as for a "problem," neither one of us that, but one of us is very much mistaken, and because the context of Acts 2:38 is consistent with other statements along the same lines that Peter made in Scripture, namely in 2 Peter 1, the mistaken one is you. Peter is not inconsistent with or contradicting of himself, as you would (inadvertently) make him out to be.
Additionally, you and those holding to the same viewpoint are making baptism out to be a work that earns one ~ or makes one meritorious of ~ salvation. This cannot possibly be the case, as no work of ours can merit our salvation; Scripture is very clear on that point. In addition to that, it makes God's grace out to be something other than grace, which is unmerited favor.
So, not to say that "you have a problem"...
... but in view of the above, surely you see issue you run head on into.
LOL!
The validity of the substitution is perfectly valid, as Peter's context in Acts 2:38 is perfectly consistent with His context in 1 Peter 2:10.
Grace and peace to you. Especially grace, as you seem to be so lacking in it.