He didn't want to share the information because no one else had this massive weapon and it was the first of its kind to be made. And most of the info got leaked to the Soviets and Britains by scientists who worked on the bomb, fearing that the US might be too strong with this power.
He wanted to seem like the U.S. had a bigger and better weapon than the rest of the world did so they would not be hostile to us. he supported giving it to Britain and the Soviet union because they supported us and allied with us in the war
early Christians seems to imply that the Romans still believed in the roman versions of Greek gods. it was not until Constantine came to power that they accepted Christianity
