fter the Archdiocese of St. Louis invited people molested by priests to seek healing from the Roman Catholic Church, Arthur Andreas reported earlier this year to archdiocesan officials that he had been sexually abused by the Rev. Alexander R. Anderson in the 1980's.Mr. Andreas kept his accusations strictly confidential, speaking of them only in private with the church authorities, and he did not sue either the archdiocese or Father Anderson. But the priest made the accusations public in April, when he used his pulpit to deny them, and he subsequently sued Mr. Andreas for defamation.Yesterday, Mr. Andreas countersued in a Missouri court, asserting that Father Anderson and the St. Louis Archdiocese had injured his reputation by making the dispute public in the hope of intimidating him into retracting his accusation."I didn't want a cent," Mr. Andreas, a 28-year-old carpet salesman, said yesterday in an interview. "All I wanted to do was to respond to the Catholic Church, which had opened its arms to me. I thought this would be a healing opportunity. But the church invites you to come closer and then they bite you."