I think the first group might have a valid reason, but the second, well I know that many church's (both liberal and conservative) have tried to remove all mystery from faith, but truth be told, faith is all about the unknown.
I love mystery - the bread and wine of the Eucharist (Communion); the Word made Flesh; the uncertainty of Jesus' parabolic ministry; redemption; etc - and I think the Church should be all about helping people sit in the midst of paradox certainly only that they are uncertain. And so, I am drawn to this great piece of poetry from 2 Corinithians, "We are treated as impostors, and yet are true; as unknown, and yet are well known; as dying, and see-- we are alive; as punished, and yet not killed; as sorrowful, yet always rejoicing; as poor, yet making many rich; as having nothing, and yet possessing everything." I'm drawn to it because it is precisely what I think it means to follow the God of all mystery - the one who is completely unknowable yet desires that we come to know him.
Today is a day for mystery