Perhaps the solution is to stop claiming Christianity is the only way to have a relationship with God — problem solved. Oh, and stop sexually abusing children and then covering it up, that would help as well.
I’ve observed most people who leave Christianity (including myself), do so because of the hypocrisy, greed, racism, sexism and homophobia, not because secular activities offer the same metaphysical experiences.
Exclusivity is exactly the reason people are leaving, they desire to live authentically, without judgement…