No longer a Christian, but I grew up quite passionate about my faith. Here are my two cents:
Your objection is spot on. It's a common critique and conundrum that Protestant Christians have been wrestling with and philosophizing about for quite some time.
The Christian bible is riddled with contradictions, absurd pronouncements, and obviously bad advice. However, my thinking is that those are where the meat of Christian practice lies. A bible, itself, is simply ink on lots of pages, while it is a spiritual practice to try deriving meaning and value from the jumble.
Newtonian mechanics, Maxwell's equations, Quantum Field Theories; all of these excellent descriptions of our world each contain absurd infities, false predictions, and sketchy philosophical foundations. However, the standard rhetoric is that these cracks are where all the interesting research happpens!
While I reject Christianity for personal reasons, in my experience, choosing some spiritual conundrum and working hard to resolve it goes a long way to generating personal spiritual growth, whatever that means. At the very least, many find such work deep and valuable and meaningful.
::fist bump::