Washington, D.C. ? President-elect Barack Obama on Thursday defended his selection of megachurch pastor Rick Warren to deliver the invocation at his inauguration, saying that he disagrees with the minister’s opposition to abortion and same-sex marriage but that there should be room for “dialogue” on such difficult social issues.

Liberal groups and gay rights activists were outraged at the choice of Warren, one of the country’s most prominent evangelicals, who has spoken out in favor of a ban on same-sex marriage in California.

Although Warren’s views are not far from those of other clergy members who could have been asked to deliver the invocation, Obama found himself emphasizing his own record as “a fierce advocate of equality for gay and lesbian Americans.”

“It is important for America to come together, even though we may have disagreements on certain social issues,” Obama said.

He emphasized that Joseph Lowery, a founder of the Southern Christian Leadership Conference, will give the benediction and has “deeply contrasting views to Warren on a whole host of issues.”