I suspect the USSR without Gorbachev as leader would inevitably have imploded anyway! Reagan was according to Wiki, intrigued by the possibilty that Gorby was a closet Christian from his summit talks with him. He was actually baptised as a Russian Orthodox church member as a child.
Mind you, given that he was born in 1931, being a committed Christian at that time may have another meaning ie to the Gulags or later to a mental institution! Another way Gorbachev's career may have not risen to the heights is if he became a law professor at Moscow State university, indeed many things could have curtailed it.
A friend of mine, an ex-Marxist says Gorbachev was the least successful political leader of his era because he ultimately destroyed the system he came from and presumably wanted to at some level maintain.