Yes 1 example of effective prayer is the revelation prophetic nature that Paul speaks of in 1 cor. 14 25.
Praying 4 someone and telling them what the h.s. reveils
Is what occurs in the prayer groups that is led by the h.s.
There should be examples of answered prayers
I know the plans I have for you says scripture . this type of prayer does bring as saint Paul says. Edification and comfort
So how does it work with you??