(CNN) -- Gene Robinson, the first openly gay bishop in the Episcopal Church, said Saturday that death threats and continued worldwide controversy about his selection contributed to his decision to retire in January 2013.
Robinson's announced retirement surprised many of those attending the annual diocesan convention in Concord, New Hampshire.
The bishop, who has served in the post in New Hampshire since early 2004, said he is energized about his next two years of ministry and support of clergy and congregations as the process of naming his successor moves forward.
But turning 66 in 2013 and the "constant strain" from the church schism were factors in his decision, Robinson said in prepared remarks. The bishop said he is in his fifth year of sobriety after receiving treatment for alcohol abuse.
"The fact is, the last seven years have taken their toll on me, my family, and you," he told those attending the convention. "While I believe that these attitudes, mostly outside the Diocese, have not distracted me from my service to you, I would be less than honest if I didn't say that they have certainly added a burden and certain anxiety to my episcopate."
Conservative factions in the Anglican Communion, a 77 million-member denomination worldwide that includes the Episcopal Church, have opposed the ordination of gay bishops. Robinson's appointment prompted a semi-official moratorium on naming new gay bishops, but they revoked that ban last year.
In May, the Episcopal Church consecrated its first openly lesbian bishop in the face of objections from some conservative Anglicans.
A number of Episcopal dioceses broke with the official church structure, forming the breakaway Anglican Church in North America in protest of the church's stance on homosexuality.
After his selection in 2003, Robinson told CNN he was prepared to serve as bishop.
"The only thing that is sort of weighing on my heart is knowing this is very difficult for many people in our church, and for those people for whom this is confusing or disturbing," he said. "I'm very sorry about that. But I am feeling very calm about moving forward, that this is in fact what God wants for me.
Although he has often spoken about his sexual orientation, the bishop told the audience Saturday that he doesn't always wanted to be identified with it.
"New Hampshire is always the place I remain, simply, 'the Bishop,'" he said. "This is the one place on earth where I am not 'the gay Bishop.' I believe that you elected me because you believed me to be the right person to lead you at this time. The world has sometimes questioned that, but I hope you never did."
Robinson, who is in a same-sex relationship, said he has evangelized gay and lesbian people in order to "make the case for God and God's Church."
He also made reference Saturday to the recently publicized suicides of gay and lesbian teenagers.
"[They] have taken their own lives because religion tells them they are an abomination before God and who believe their lives are doomed to despair and unhappiness," the bishop said. "I go tell them a different story."