The scientific study of mental functions and behaviors is antithetical to God?
FWIW, I am a big fan of nouthetic counseling, a biblical approach to counseling first proposed by Jay Adams and more recently associated with David Powlison and others. I appreciate the work of the Christian Counseling & Educational Foundation (CCEF).
That said, I maintain that God conceived of our “mental functions and behaviors,” and enjoys when people study these things. I also maintain that God does perform miracles, and sometimes He transforms people over time.
So, explain how saints throughout the centuries went WITHOUT what "Christian psychologist" claim is indispensable to treating their patients.
It is pagan from its roots, and it cannot be "Christianized."