Theology is simply the study of God and God’s relation to the world. Theology is essential to life, both eternal life…

And this is life eternal, that they might know thee the only true God, and Jesus Christ, whom thou hast sent. [John 17.3]

…and daily life.

All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: That the man of God may be perfect, thoroughly furnished unto all good works. [2Timothy 3.16-17]