Why is it important to learn more about God (Theology)? Christ says, "Now this is eternal life: that they may know you, the only true God, and Jesus Christ, whom you have sent (John 17:3)." God wants us to know him. Many times we as Christians focus so much on our actions and forget that our actions are based on our knowledge of God and his commandments. How can we expect to please God unless we know what pleases him? How can be obey him unless we know what to obey and know how to obey it.
Our lives are based on three things: Knowing, Believing and Doing. For example, first we must know that God says we must teach all nations, then we must believe it, for only then can we possibly do it. A faith in God must be based in the knowledge of God. If it is not based in real knowledge of God, then it is based on what we make up or happen to believe. And faith based on what we would like to believe rather than what is God's Truth, is faith grounded in false beliefs, no matter how sincere you might be.
God's Mission is the Praise of His Glory. We must know his attributes if we are to praise him. One who knows only a little about God can only worship God a little. If one only understands God's Love but does not understand his justice, that person limits his worship of God. One who understands both can worship God for both attributes, and therefore is better able to praise God (which is man's purpose).
It is important to learn more about God (Theology) so that we can worship and serve him better, and therefore glorify him more.