I'd suggest that things went better because your cousin wanted them to and because your cousin needed a psychological impetus to do so. Your cousin needed a change, but needed an excuse to make the change.
He was given an excuse, made the change, and because things picked up you have attributed his change in fortune to God, not to himself.
I find that a pity, that you have been convinced that his fortune is not of his own making. Change in one's surroundings is often a catalyst for change of fortune. One does not need God for that.
As previously said, you seem to find psychological benefit in the belief in God, but that itself is not evidence or proof of the veracity of what you believe in, only of the psychological benefits you have felt from the process of believing.