The passages from the Holy Scriptures on homosexuality must always be understood against the background of their time, Kohlgraf said in a programme broadcast by Südwestrundfunk (SWR) on Sunday morning.
The bishop emphasised: "I don't take a half-sentence from the Bible and say: this is the half-sentence that applies to everyone without question."
He went on to say that "you cannot simply derive timeless, eternal truths" from biblical passages on homosexuality.
Rather, the current findings of the human sciences must always be taken into account. He treats biblical texts differently "than just using them as a quarry".
Today, scientifically based theology is "considerably more advanced".
Kohlgraf went on to say: "There are professed homosexual priests in Germany, and they are good pastors."
He emphasised that it is now possible to talk very openly about homosexuality in the Catholic Church in Germany. Kohlgraf (58) has been Bishop of Mainz since 2017. He spoke at the SWR Democracy Forum in Hambach Castle on the topic of "Taboos in our society - between morality, power and the media".
Other guests on the panel, which was moderated by publicist Michel Friedman, were filmmaker Mo Asumang and journalist Ronen Steinke.