Theology is important to the Christian existence because a faith without reason is an unexamined faith. This faith is weak as it is untested, and it also is unfulfilling as the person with an unexamined faith does not know his God well. Theology is the pursuit of God, the desire to know Him more. Christianity is a relationship with God, hopefully with the same desire.
Not all Christians who are pursuing God may realize they are “doing” theology. That is to say they may not set out to deliberately study God in an academic fashion. This is not necessary. The simple act of exploring faith, dwelling in God’s revelation, or getting to know God better through His revelation is doing theology.
That is not to say that more understanding is needed in order for belief to survive. Theology is “faith seeking reason,” but we do not seek understanding in order to believe, we seek understanding because we believe.
Theology is the language the Church uses to communicate within the body. The dialogue theology provides allows the Church to change as the times demand without losing the essentials of Church life. This dialogue within the Church is a vehicle the Holy Spirit uses to work in and through the Church.
Ultimately, theology is necessary to fulfill God’s most basic command to Christians. In order to share faith with others, Christians must have first processed what has happened in their lives into words. This is theology in its most basic form. The more Christians do theology the more effective witness will be to a greater amount of people.