Part of my testimony is due to my study of other theologies and religions. Frankly, I don't "desire to believe" any of them like I desire to believe what is taught within "Mormonism" and The Church of Jesus Christ of Latter-day Saints. It really is my foundational desire (what I want), so I've chosen to pursue a deeper understanding of it - to reconcile what I can reconcile and gnaw on what I can't reconcile for now, with an understanding that much of what we believe is our best attempt to understand a little better what can't be understood. It works for me.
It also has given me a bit of perspective on "the alternatives" - again, enough to realize that I just don't want them. They won't give me any more joy in the here and now than I already have, and they don't give me the hope for a continuation eternally of what brings me joy in the here and now. I feel what I believe is true; I want it to be true; I don't want any radically different "truth"; I accept the concept of continuing growth and revelation (the evolution of understanding that will continue to change my perspective) - so I accept the difficulties inherent in the history of the Church as a natural result of mortality, and I pursue the joy I want and for which I hope.
I could make religion a very complicated thing if I chose to do so, and I could get all wound up in knots about it if I chose to take that route, but I have SUCH joy and peace and wonder in my life without doing those things that it would be folly to do so. I also am just humble enough to realize that I always will see through my religious glass, darkly, no matter how hard I try - and, at the core, foundation level, that is a fundamental principle of Mormonism. It might get lost in the natural tendency to want to know it all RIGHT NOW far too often, but it's there, nonetheless.
43 minutes ago