Don't you think more Christian churches need to be more weary and cautious adult converts?

No, I do not think we need to be questioning one another's faith according to any doctrine of man. I think we are supposed to recognize, as God's Word tells us, that each man is given a measure of faith as God sees fit. I also think we are supposed to be building each other up not tearing down. Only God can judge the heart. I sincerely hope you will reconsider such position.God bless.