Upper Bann MLA Robbie Butler said he took severe criticism on social media from nationalists and unionists for accepting the invitation.
The words he heard personally from the Pope on child abuse on Saturday sounded “almost like platitudes” he said.
On Sunday Pope Francis went on to beg forgiveness for members of the Catholic Church’s hierarchy who “kept quiet” about clerical child sex abuse during Mass at Dublin’s Phoenix Park.
But Mr Butler was still not won over.
“Some of the words may bring consolation but words without action will not bring restoration or restitution,” he said. “Any words must be followed up by action including making sure that any claims of abuse and cover-up made in the past are handed over to the police.
“It would also be good to see the church put in place practical measures of support for victims. The time for words is now done.”
Mr Butler thought it positive that during his visit, Taoiseach Leo Varadkar also took responsibility for the failure of Irish state agencies to prevent child abuse.