The first openly gay bishop in the American Episcopal Church has recently said he “can’t believe the progress we have made” regarding the passage of gay rights in the US, since he would not have dreamt of growing up seeing same-sex marriage legalised in 15 states.

According to the Pittsburgh Post-Gazette, the now-retired Bishop Robinson said that only 10 years ago, when he was first ordained, there was no place in the country he could marry his long-time partner.

Speaking to a gathering of around 50 people at East Liberty Presbyterian Church on Saturday, he said: “I can’t believe the progress we have made.

“If you are anywhere around my age, you could not have dreamt in your growing up that you would see what you have lived to see.”

Bishop Robinson said the recent changes are due to decades of activism, including many people stepping out of the closet.

“Coming out is the most political thing you can do,” he added, citing Harvey Milk’s speech: “If they know us, they’ll love us.”

Despite this, he also acknowledged the longstanding struggle both the church and state endure when it comes to supporting gay equality. He added that Pittsburgh has been “ground zero” throughout the debate.

One member of the audience, Regis Smolko, asked Bishop Robinson how he responded to critics such as some bishops who had spoken of homosexuality as “satanic.”

Bishop Robinson responded: “The most important thing I’ve learned in the past 10 years is that how someone treats me does not relieve me of my responsibility to treat them like the child of God they are.”

He added: “Some day, I’m going to be in heaven with those guys.”

Gene Robinson retired from his post as the Bishop of New Hampshire at the start of 2013. Recently, he won an award for personal courage, compassion and commitment to advance the human and civil rights of lesbian and gay Americans.

Previously, he said that Jesus would have approved of gay families and of LGBT relationships in general.

In 2010, he talked about what it was like growing up in his time, saying:  ”It was almost like committing suicide to understand yourself to be a homosexual person. It’s hard to remember how the world has changed so much in these last 20 years.”