didn't pay in, first.

It did say they will have to have the qualifying credits which I hope means they have already paid into the system. Otherwise, their credits should start the day they sign back up again.

Per the IRS, they're covered under SECA (self-employed), and not FICA (all clergy are covered by SECA -- per IRS and CFR -- Clergy Financial Resources)
No clergy have to pay into SECA if they get an IRS exemption. Which is probably the group they are talking about in this article.
But, (per IRS) they are not covered under SECA as well.
The most nuns can received from Social Security is 277.75/mth (because of vow of poverty. source CRG Christian Faith Guide). This is because of their vow of poverty -- Not sure how that works. I'm guessing it is about how much they put in through SECA because they make little money themselves, especially if you're in one of those vow of silence abbeys.
Teaching order nuns and Nursing Order nuns make more money and so they pay more into SECA. I guess that means they may make more in social security
Priests are harder to gauge. They, like the nuns (and all Catholic clergy) pay into SECA, unless they get the exemption from the IRS, so they are eligible for Social Security. I'm guessing that if you are a priest that belongs to a 'vow of poverty' religious order, you get 277.75 a month.
If not, they probably qualify for more. Being a cardinal, the amount of money they get is probably fairly decent-to-quite grand; I don't know what a cardinal makes, but I'm guessing it's more $1000 a month.
I could not find any place that said that Catholic clergy take the SECA exemption, so I guess they are expected to pay into it.

If this law is for members of the clergy who took no exemption, and paid into it, but never applied for the social security money they paid into, then it doesn't seem unfair to give them the money they're entitled to under SECA.
If it's the freeloaders, who got the exemption and never paid into it -- too bad for them. Personal responsibility and all that.

The group I worry about, and if it covered them, I'd have no issue with any changes, are those classified as 'Religious Worker.'
They are not paying into SECA "if your employer elected to exclude you." (IRS).
I am curious why their employer gets to elect to exclude them? Why aren't they allowed to make this decision? And, is this explained in detail to them, so they don't get blindsided later in life?

You irrevocably waive any right to OASI/social security and that's it. Or was it, if this bill becomes law.

Left out: If you worked 10 years and then joined the clergy and signed the form, you're revoked your eligibility. So the 10 years doesn't matter. (As a teacher in Texas, I'm covered by TRS--but I'm eligible to receive SS when I apply because being covered by a DCP for the last 20 years doesn't affect my previous contributions or eligibility. I signed no irrevocable waiver.)

I said the text is mostly clear. This bit curls around and tries to go all ouroboros as though that would be fattening:

Because Social Security is a pay-as-you-go system, any benefits paid would be funded by the clergy members’ own contributions.

Yes, SS is a pay-go system: What's paid goes now for current expenses. That is, a payer's 'own contributions' funds current payments--so unless the claim is that you pay in $200 and get $200 back, what you are paying as FICA is equal to or greater than your current benefits, the sentence is gibberish. Any benefits paid (in the future) will be funded by future payers' contributions, or the benefits will be reduced (most recent estimate I've seen is in the mid-high-teen percents but people like using the scarier older one).

This is not neutral, since most of the time, these days, people pay in less than they get "back". Hence the current reduction in the 'trust fund'. Contrary to claims of 'theft' often bandied about without understanding, by law it had to be placed in special issue treasury bills and is currently gradually, but soon to be quickly, being redeemed, at no increase to the national debt as calculated one way but at an increase in publicly held debt--by which I mean not 'debt held by the federal government' but 'debt held by individuals, investment funds, pensions, and, weirdly, the Federal Reserve'--sure to create some problems with the debt-issuance system (and maybe the federal deficit).

It's fairness. While I don't want to see anyone reduced to poverty in old age no matter what their persuasion, if they didn't bother to pay in to support prior and existing SS recepients, I don't think current and future workers should support them. Need a compromise on this one. A penalty perhaps for short sightedness, but we won't let you starve.

Why is this happening now? Who is behind this? Or should I ask, how many people are asking for this?

House - Rep. Vince Fong Reintroduces the Clergy Act with Rep. Mike Thompson

Senate - U.S. Senators Maggie Hassan, Katie Britt Reintroduce Clergy Act, Support America’s Faith Leaders

The links describe their thinking. Per the Senators' description, this option has apparently been given several times in the past -

So it sounds like those past "openings" may have been "one-off" opportunities and then expired or sunsetted after some period of time.

Special rules for special people based on their "beliefs". It's been my experience there is a rather large gap between professed beliefs and actual beliefs. That is, if beliefs actually influence actions.

they sign back on to the system.

I’m usually very charitable, but I don’t see how we can let them start ‘collecting’ unless they have paid their share just like those of us who paid in for decades while working.

I mean, there are people who have to pay a penalty FOR LIFE for drug coverage if they didn’t initially take out a plan that included drug coverage when they first signed on to Medicare. That policy is an obscenity.

Our country is about two things: profit and financial pain

churches, or any "religious" org. don't pay taxes already
this is just another way to harm SSI
calling it a "non profit" doesn't mean anything

I wonder about the source of that advice and what they were told

They should just pray. I’m sure the wealthier ones, like Joel Osteen or Creflo Dollar, et al., would see the kindness in their hearts to donate to the impoverished clerical members. Maybe tap into the Pat Robertson trust fund?