Theology is very important. Theology is essentially the study of God. God created everything. Thus, theology is important.
More eloquently put, theology delves into the essence of the universe and the cosmos and attempts to know better the One who created it all. This is a lofty thing to achieve - to know the creator of the universe more intimately. The One who created everything is infinitely smarter, more capable, and wiser than myself - so why would I attempt such an endeavor? Because I am a Christian. I believe that all Christians have a responsibility to get to know their God. We have the ability to pray to God. I don't know about anyone reading this, but I like to know who I'm talking to some extent. I also like to know who wrote The Bible that I tried to read more often than I do. These are important things to me, and thus theology is important to me.