Dozens of Orthodox priests took Russians by surprise this week to defend jailed anti-government protesters, breaking ranks with Church authorities who for years have aligned themselves with the Kremlin.
Experts say the move is part of a quiet revolution in the powerful but opaque Russian Orthodox Church, with a generation of clerics increasingly willing to criticise their superiors.
In an open letter, the priests asked courts to reconsider "repressive" jail terms handed down to six people over demonstrations this summer calling for fair elections.
The sentences "look like they are (intended) to intimidate Russians," said the letter, which has so far been signed by 124 clerics.
"We want to express our hope that Russian citizens will live with trust in the justice system."
The clerics published the missive without the consent of the Church administration -- led by the influential Patriarch Kirill, a staunch ally of President Vladimir Putin.
One of the clerics who signed the letter, Father Konstantin Momotov from the southern city of Volgograd, told AFP the move was "about simple Christian care for people who need it and nothing more."
He insisted there is nothing political about it and that it is not hostile to church authorities, which he has served for 25 years.
"If I see that someone needs protection, as a priest I want to take part in that," he said.
- 'Brave and deeply Christian' -
Another priest who signed the letter, Father Yevgeny Lapayev whose parish is in the Siberian city of Tyumen, also stressed the act was apolitical.
"I just thought that the measures taken by authorities and the courts have been excessively harsh," he told AFP.
Widely shared on social media, many Russians welcomed the letter, some saying it was overdue.
In an editorial, the Vedomosti daily called it a "brave and deeply Christian step that a part of society has been awaiting for a long time."
"There has been nothing like this in years," said church expert Ksenia Lutchenko. "It was completely unexpected."
"They were able to unite without the church leadership and express a clear Christian position: to ask for mercy for prisoners," she said.
No individual high ranking Church official has commented on the letter, with the synod only releasing a statement saying the priests do not have the legal knowledge to comment on the jail terms.
- Preaching to the young -
What makes the religious intervention unique is the diversity of the clerics.
Aside from well-known liberal priests from Moscow and emigre clerics, they also include many low-ranking priests from all over Russia.
Roman Lunkin, an Orthodox church expert at the Russian Academy of Sciences, said the rank-and-file clerics in the provinces face the biggest risks for going "against the system".
Lunkin said many had been dissatisfied with the direction of the Church for some time, and the only surprise is that "it has not spilled over before now".
He called it a "Church revolution" mainly driven by priests in their 40s and 50s.
"They do not like that the Church is so closely associated with the authorities and the State machine," he said. "They say this harms their mission of preaching to the young."
In these circles, he said, priests are less afraid of the episcopates, the Orthodox Church regional authorities, on whom they are "completely dependent."
Lunkin said it was not yet clear how far the episcopates in the regions would go to punish others for signing the letter, or if Patriarch Kirill will publicly comment on the issue.
- 'Absolute obedience' -
Dmitry Sverdlov, a former Orthodox priest who fell foul of the institution over its position on the 2012 Pussy Riot case, said the priests will "inevitably" face consequences.
"They might not be major or public, but there will definitely be some because the Church system demands absolute obedience," he told AFP.
He said a common method of exerting pressure on provincial priests, who often have families, is to lower their financial allowances to a "bare minimum for survival".
Since 2012, Sverdlov said the patriarchate has unleashed "huge resources" to sideline critics within its ranks, with Patriarch Kirill then calling them "traitors in robes".
Church expert Lutchenko said the patriarchate is likely waiting to see if the State will backtrack on its crackdown on protesters before deciding what to do with the rogue priests.
She said the act was an "important shift", regardless of consequences.
"It showed that priests are willing to take risks for the people," she said.
According to the Pew Research Center, 71 percent of Russians identified themselves as members of the Orthodox church in 2017.