The bishops made their statement in response to the case of a 28-year-old woman, R Subashini Saravan, whose husband of five years became a Muslim convert without her knowledge and who also converted their three-year-old son. The couple have another two-year-old child.
While Ms Subashini wished to end the couple's marriage in a civil court, her husband, businessman Muhammad Shafi Abdullah, formerly T Saravanan, 31, applied to the Shariah court to end their civil marriage.
According to news reports, Ms Subashini fears that as a non-Muslim mother fighting to keep her children, the odds may be against her in a Shariah Court. She says her son became a Muslim without her knowledge.
As a non-Muslim, she says she should not be forced to seek redress in a Shariah Court, contrary to the Malaysian constitution.
In a statement read out at all churches on Sunday, Malaysia's bishops say that they "are deeply disappointed and feel aggrieved by the recent majority decision of the Court of Appeal that the non-Muslim wife had to seek recourse through the Syariah Courts.
"This is a form of religious oppression and an affront to human dignity," the bishops say in the statement signed by Kuala Lumpur Archbishop Murphy Pakiam.
"As the Federal Constitution is the supreme law of the country, a person of one religion should not be made subject to laws of and governance by another religion. We urge all to voice their grievances against the injustice through proper channels.
"Let us do all that is possible and also pray that justice and freedom of religion be restored," the bishops said.
Some commentators have warned of a possible "constitutional crisis" over the ruling.
The case of R. Subashini Saravanan (Mental Jog, Lucia Lai Blog (3/4/07)
Subashini's case: Constitutional crisis in the making!(Screenshots, Jeff Ooi Blog, 3/4/07)
LINKS (not necessarily endorsed by Church Resources)
Archdiocese of Kuala Lumpur
Malaysian Church besieged over conversion rumours (CathNews, 7/11/06)
No joy for Malaysian Muslim convert to Catholicism (CathNews, 25/8/06)
3 Apr 2007