The story of the church's defection from pure sacramental ordinances is not a short-and-sweet, and bright-and-early step. It is actually a series of steps, and fairly drawn out over the course of time from the post-apostolic age to the beginning of the Medieval period (around A.D. 600). And even much later, Rome herself undertook some steps at rectifying her accumulated errors, by reducing between fifteen and twenty sacraments (depending on where you were) down to seven, fixed, for everybody.
The 16th century recovery, by comparison, was fairly sharp and well defined. But even then one finds a continuum, all the way from those who desire no changes in the church practice (Rome) through the Lutherans and Anglicans, to the Reformed, to those who went further to reinventing what we know as sacraments, or abandoning them entirely.
Recognizing that by about the third century (A.D. 200) the seeds of baptismal error had sprung into vigorous sprouts (as also with communion), should this force us into a reconsideration of whether these alleged defections from purity were, in fact, error? Well, it's always worthwhile to review the reasons for why one holds for true the things he does. In fact, that is what led the Reformers to review the things Rome taught as faithful practices--and to reject those that were false, regardless of how old the pedigree of the error.
It is a bit speculative, trying to ascertain
why the church took a particular route, when so little written material (besides the Bible) is left to us from the first three centuries, A.D.--which included desperate times of persecution. But it does seem reasonable to conclude that in one sense, the church's unwavering determination to stick firmly to the exact words of Scripture could, under certain stresses, lend itself to an overly literalistic interpretation of those very words.
So, if "baptism now saves you" (1Pet.3:21), and if the sign and the thing signified are completely identified with each other, then the ritual act rightly executed might reasonably be conceived as effecting the spiritual reality itself. Imperfect understanding could be repaired. Whereas, if the words were lost that taught the true meaning, all would be lost. So the church stuck very close to both the words associated with baptism, and to apostolic practice during those difficult days.
The church also lost an important spiritual relation in those early centuries through increased alienation from the Jews. The predominantly Greek/Latin speaking church had the OT in other languages. What was being lost was the way the OT formed the connection between the people of God of old, and the present mainly Gentile constitution. The Scriptures written by Jews were no longer being taught mainly by those of Jewish heritage in the church. Jews starting with the Apostles were the original leaders and teachers of the church. Elders in the synagogue became elders in the church. I think the Jewish worldview resisted viewing sacraments as
incantations better than the Gentile, still influenced by pagan/magical superstition. But the Gentiles were inevitably coming to dominate by sheer numbers.
Furthermore, the church was preoccupied (besides with survival and Scripture) with preserving crucial doctrine--doctrine of God, doctrine of Christ, etc., against the rise of the heretics and the challengers. Coming out of the persecution time, most of her energy and mental effort was given up to maintaining identity in the truth. So again, sacramental practice seemed to be going along fine, more-or-less faithful to the apostles' "how to," even while the rationale was suffering.
Then, there was the Mystery-religion competition. Christianity had two, simple, authorized rites. The competition had lots of elaborate rites, secrets, cool stuff. It was almost inevitable that the church would elaborate on her rites. At first no newly devised activity could be conceived on par with the apostolic ordinances. The associated rites were called "sacramentals." Naturally, they would vary from place to place; but just as naturally the activity in one place migrated elsewhere. And these extra rites grew in importance. And eventually they were practically sacraments and just as mandatory; and they proliferated, and were confused. And eventually, the Roman centralized authority worked to reign it all in and make it uniform, and fixed the number of sacraments at seven.
So, we have sign/significance conflation; loss of biblical (OT) roots for NT rites; tendency to think in false-worldview terms; focus on different vital issues; and a carnal desire to have more "powerful" rituals. Any of these, or all of them together,
could (I'm not going to be more definite than that) produce a series of smaller defections that eventually lead to widespread misunderstanding after just a few centuries.
We are less interested in the centuries it took to get to a place the Reformers tell us was a church in abject disrepair and cluttered with an incredible amount of junk. And we are more interested in the steps they took to recover the apostolic beauty of the "simplicity of Christ," 2Cor.11:3. The key, of course, was reading Scripture according to authorial intent, rather than according to changing whims of church-authority. Rather than glory-rituals, the Reformers preferred the "foolishness" of the cross and God, 1Cor.1:18,25, his appointed means connected to his promises to bring about salvation. The Reformers put the emphasis on faith (the Bible's emphasis), rather than on work; so that the key thing to effectiveness and appreciation of the church's sacraments was believing what they taught. Faith put sign and signification together for a participant's benefit.
The literal, simple words of Scripture are powerful, and they will bring about a great, saving effect when one believes in the God who condescends to meet us in these paltry (to men's eyes) means.
Heidelberg Catechism 72-73
Question 72
Q. Does this outward washing with water itself wash away sins?
A. No, only the blood of Jesus Christ and the Holy Spirit cleanse us from all sins.[1]
[1] Mat.3:11; 1Pet.3:21; 1Jn.1:7.
Question 73
Q. Why then does the Holy Spirit call baptism the washing of regeneration and the washing away of sins?
A. God speaks in this way for a good reason. He wants to teach us that the blood and Spirit of Christ remove our sins just as water takes away dirt from the body.[1] But, even more important, He wants to assure us by this divine pledge and sign that we are as truly cleansed from our sins spiritually as we are bodily washed with water.[2]
[1] 1Cor.6:11; Rev.1:5; 7:14. [2] Mk.16:16; Act.2:38; Rom.6:3-4; Gal.3:27.