Jonathan Edwards said, “Of all kinds of knowledge that we can ever obtain, the knowledge of God, and the knowledge of ourselves are the most important.”
I can trace all my success and my failures to this one truth. My faith is stronger, my desires are more correct, and my obedience is easier when my knowledge of God and/or the knowledge of myself is increased. And on the other hand, I am more prone to sin, worry, and fall into unbelief when I neglect the knowledge of Him and/or myself.
What I need most is the true knowledge of who He is and who I am. Not a delusional self-esteem stroking knowledge of how wonderful I am but truly how bad and depraved I really am. And how far God is really and eternally above and beyond us.
The more I can know about those two things the better off I am. So yes, it important what the church teaches, particularly about God and about me.