In 1 Peter 3:21, St. Peter writes, "baptism...now saves you."
Baptists, of course, explicitly teach that baptism does not save you.
Baptists must implicitly assume that Peter actually believed like Baptists believe, that baptism does not save you. (I say must because we are dealing with a binary possibility here: does or does not. If you don't believe one, then you must believe the other.)
If they assume that Peter-the-Baptist believed what they believe, they likely assume that why he believed baptism does not save is the same reason why they believe that baptism does not save. Thus, Baptists implicitly assume that Peter-the-Baptist thought of baptism as an outward ritual involving water only, and that the Spirit is in no way involved, that no grace is imparted during the ritual, and that nothing happens within the soul of the person baptized.
But if Peter-the-Baptist believed all these things, why would he then say baptism now saves you? Why would he say that a grace-less, outward sign saves you? No Baptist pastor in a million years would say that baptism saves you.
Peter's expression plainly and simply doesn't make any sense if Peter really thought like a Baptist.
Further, why does Peter unpack the idea that baptism saves you by describing its action as an interior action, when he knew full well that no interior action occurs during a baptism, since the interior change already occurred previously (according to Baptist theology)?
Moreover, why does he connect the ritual and imagery of baptism in the New Covenant with the time point in the Old Testament when Noah was saved through water? Doesn't this dramatize the idea that baptism saves you now, which is the very point that Peter-the-Baptist would never want to make?
Finally, lest we blame Peter-the-Baptist for a temporary verbal indiscretion, might we ask what the Holy Spirit who inspired this text was thinking? Is this not the same Holy Spirit who knew that Christians from the very beginning of the Church would begin teaching consistently and universally that baptism now saves us, and would do so for 1,600 years until the Anabaptists came along to set things right? Why didn't the Holy Spirit ward off this dangerous, work-based, false teaching by inspiring Peter simply to preach "Baptism does NOT now save us"?
My dear Baptist readers, it is not your job to answer these questions. Rather, I would recommend that you ask these questions to your pastors, Bible-study leaders, and Bible teachers. Ask all of them; don't let them dodge the bullet by not letting you fire it. Ask your pastors and weigh their answers against what Peter taught in 1 Peter 3:21. Think critically about the answer you are given; do not assume that it is correct until you have critically verified it as such. (After all, the whole point of the exercise is really to test your Pastor's teachings by God's word, just like the Bereans did in Acts.) Compare their interpretation of this passage with how others have interpreted the passage historically. How did the early church fathers who learned the faith from the apostles understand baptism?
Do some research. Think critically. Love the truth. Seek the truth. And the truth will set you free!