The Folly of "Immersion Only Believer's Baptism... Only"

I used to hold that the only valid baptism was a believer's baptism (consenting confessing adult) by immersion (full dunking). Not only was that requirement not Biblical, I never stopped to consider what that means.

Using some rough estimates, here is what this accusation says when taken to its logical conclusion:

1.115 billion Roman Catholics are not properly baptized.
225 million Eastern Orthodox are not properly baptized.
75 million Calvinists are not properly baptized.
75 million Methodists are not properly baptized.
73 million Anglicans are not properly baptized.
72 million Oriental Orthodox are not properly baptized.
70 million Lutherans are not properly baptized.

...that adds up to almost 1.75 billion Christians currently living who are not properly baptized according to your particular interpretation of some pretty vague passages. It doesn't end there. Imagine if we add to that total the incalculable sum of all the Christians who ever lived and held to these denominations dating back to the early church. That is a HUGE majority of the church. This immense throng of your brothers and sisters were all baptized as infants.

You are saying they were never baptized and their rite is an erroneous violation of Holy Scripture. That's a pretty serious charge to make.... especially when you have no Biblical text that explicitly forbids the practice.

It's okay to make a charge that accuses so many faithful in all times and places if it is clearly supported by Scripture, but this is why the burden of proof is on the Anabaptists. The church shouldn't have to defend itself from such an unwarranted attack. Where is your clear proof? You are the ones accusing the majority of the current church and all or their ancestors of not being baptized in accordance with Christ's institution. That is a more serious charge than you realize. Since you consider baptism an ordinance of God, those who do not follow it are being disobedient. You are accusing 1.75 billion Christians and all their ancestors of disobedience to what Christ commanded of them. One should never accuse a brother of disobedience without clear proof from God's Word... especially when that blanket accusation numbers in the billions of brothers and sisters both living and dead.

Wouldn't you want to base such a sweeping accusation that effects so many of your fellow brothers and sisters on more than just mere human opinion, a few fallible lexicons and commentaries, and a textual interpretation that amounts to nothing more than the logical fallacy called "an argument from silence"?

.......if I'm going to publicly rebuke that much of the Body of Christ, I want to be absolutely sure that I am right beyond any and all doubt. I want to be able to point to some very clear passages that support my position and clearly reject all other positions.