A Lutheran pastor who participated in an interfaith prayer service in Newtown, Conn., in the days after the Sandy Hook massacre has apologized after being criticized by the leader of his denomination for violating its prohibition against joint worship with other religions.

The Rev. Rob Morris, a new pastor who lost one of the members of his congregation in the shooting, defended himself in an open letter published by the church, saying that before the tragedy, he had spent hours with his congregation educating them about the differences between Lutheran teaching “and the teachings of false religions such as Islam or Baha’i,” both of which had representatives at the interfaith service. He also noted that, in his own prayer at the service, he had spoken about Jesus and quoted from the Bible.

“I believed my participation to be, not an act of joint worship, but an act of community chaplaincy,” he wrote.

But he also apologized.

“To those who believe that I have endorsed false teaching, I assure you that was not my intent, and I give you my unreserved apologies,” he wrote.