The row between two Scottish churches over same-sex marriage intensified yesterday when a leading Episcopalian referred in his sermon to "bigotry from the pulpit".

The Very Rev Kelvin Holdsworth, Provost of St Mary's Cathedral in Glasgow, spoke in his church on the day priests read to their congregations a letter from Cardinal Keith O'Brien, the leader of Scottish Catholics.

Cardinal O'Brien said the church would establish a nationwide commission to challenge the Scottish Government's plans. "While we pray that our elected leaders will sustain rather than subvert marriage, we promise to continue to do everything we can to convince them that redefining marriage would be wrong for society," he said.

Mr Holdsworth held a special open service yesterday, having invited straight and gay people of all denominations.

In his final sermon before departing on sabbatical, he told the congregation of some 200, which was larger than normal: "While I am away, who has the responsibility of sharing the good news in Glasgow?

"The good news is that no form of injustice will win out in the end. The good news is that we can beat back bigotry wherever we find it, even when it comes from the pulpit."

Noting that he had "stirred up a bit of a storm" with his open invitation, the Provost added: "All the churches have some repenting to do. For they seem to have conveyed the message that not everyone was equal; not everyone was welcome."

He earlier attracted the ire of the Roman Catholic Church for the wording of his invitation to the service "in a church where gay people are welcomed and not marginalised". A senior Catholic source had accused him of using "incendiary and uncharitable" language.

The service at St Mary's came as the Catholic Church said it would establish a National Commission for Marriage and the Family to co-ordinate a campaign against gay marriage.

The church had designated yesterday as National Marriage Sunday.

After yesterday's sermon, Mr Holdsworth declined to elaborate on his "bigotry" message but said: "The thing I found amazing is how busy a church can be on a Sunday morning simply by saying that everybody is welcome. That's a position that churches share across the city but somehow, by saying that this is a place where everybody is welcome, that is the message that will draw people in. Perhaps as churches we have forgotten how to say that."

Asked about the messages on same-sex marriage from the Catholic hierarchy, he said: "I think people get weary of hearing a negative message from church people. What they want to hear is positive – about changing the world for the better, about justice, about love."

Jim Whannel and Colin Johnston, members of an Episcopal church in Paisley, said: "It's a very sad day for Christianity because of what is happening in other churches."

A lesbian Christian couple, Ruth and Jaye Richards-Hill, also backed Mr Holdsworth's open invitation. Mrs Richards-Hill said: "Somebody needs to stand up and create a balance in the opinion, and I think that worked."

A spokesman for the Catholic Church declined to respond to Mr Holdsworth's latest comments

A Scottish Government spokeswoman said: "We intend to proceed with plans to allow same-sex marriage and religious ceremonies for civil partnerships because we believe it is the right thing to do, and there is significant support for legislation across Scotland.

"We are equally committed to protecting religious freedom and freedom of expression, and ensuring that religious celebrants opposed to same-sex marriage do not have to solemnise same-sex ceremonies."