This post is adapted from the ESV Study Bible, an article contribution by Erik Thoennes, author of Life's Biggest Questions: What the Bible Says about the Things That Matter Most.

The Goal of Theology

The study of theology is considered by many to be dry, boring, irrelevant, and complicated. But for those who want to know God, the study of theology is indispensable.

The word “theology” comes from two Greek words, theos (“God”) and logos (“word”). The study of theology is an effort to make definitive statements about God and his implications in an accurate, coherent, relevant way, based on God’s self-revelations. Doctrine equips people to fulfill their primary purpose, which is to glorify and delight in God through a deep personal knowledge of him. Meaningful relationship with God is dependent on correct knowledge of him.

Any theological system that distinguishes between “rational propositions about God” and “a personal relationship with God” fails to see this necessary connection between love and knowledge. The capacity to love, enjoy, and tell others about a person is increased by greater knowledge of that person. Love and knowledge go hand in hand. Good lovers are students of the beloved. Knowledge of God is the goal of theology.

More Than Knowledge

Knowledge without devotion is cold, dead orthodoxy. Devotion without knowledge is irrational instability. But true knowledge of God includes understanding everything from his perspective. Theology is learning to think God’s thoughts after him. It is to learn what God loves and hates, and to see, hear, think, and act the way he does. Knowing how God thinks is the first step in becoming godly.

Many would like to think that just being a “good” person and “loving” God, without an emphasis on doctrine, is preferable. But being a good person can mean radically different things depending on what someone thinks “good” is, or what constitutes a “person.” Loving God will look very different depending on one’s conception of “God” or “love.” The fundamental connections between belief and behavior, and between love and knowledge, demand a rigorous pursuit of truth for those wanting to love God and to be godly. Hebrews 5:11–6:3 teaches that deepening theological understanding equips one to be able to differentiate good from evil, and it exhorts believers to mature in their knowledge of God and his ways:

For though by this time you ought to be teachers, you need someone to teach you again the basic principles of the oracles of God. You need milk, not solid food, for everyone who lives on milk is unskilled in the word of righteousness, since he is a child. But solid food is for the mature, for those who have their powers of discernment trained by constant practice to distinguish good from evil. Therefore let us leave the elementary doctrine of Christ and go on to maturity. (Hebrews 5:12–6:1)

A Commitment to Truth

Good theology is based in the belief that God exists, is personal, can be known, and has revealed himself. These presuppositions motivate theologians to devote themselves to a passionate pursuit of knowledge from God’s Word. Unfortunately, the word “theologian” is used almost exclusively for vocational theologians rather than for anyone earnestly devoted to knowing God. On one level everyone who thinks about God is a theologian. But a believer whose life is consumed with knowing his Lord is most certainly a theologian, and theologians are committed to truth.

Loving God means loving truth. God is a God of truth; he is truth. In Scripture, all three persons of the Trinity are vitally related to truth. In light of this relationship between God and truth, it should be no surprise that the Great Commandment includes loving God with one’s mind: “And you shall love the Lord your God with all your heart and with all your soul and with all your mind and with all your strength” (Mark 12:30, quoting Deuteronomy 30:6). Fully loving God and obeying the Great Commandment requires actively engaging the mind in the pursuit of truth.

A Commitment to Your Neighbor

The second half of the Great Commandment—love your neighbor as yourself (Mark 12:31)—also requires a great commitment to truth. Love, kindness, and compassion must include profound concern that people understand the truth, since their lives depend on it. God meets man’s greatest need of relationship with him through an understanding of truth: “Of his own will [God] brought us forth by the word of truth, that we should be a kind of firstfruits of his creatures” (James 1:18; cf. 1 Peter 1:23). Sanctification also happens by means of the truth: “Sanctify them in the truth; your word is truth” (John 17:17; cf. Romans 12:2).

Authentic discipleship is marked by knowing and obeying truth: “If you abide in my word, you are truly my disciples, and you will know the truth, and the truth will set you free” (John 8:31–32). Therefore, loving others involves having a deep desire that they understand truth. This is the reason the Great Commission has a vital teaching element. Making disciples of Christ involves teaching them to observe all he has commanded (Matthew 28:20).

Jesus wants people to understand and obey truth and thereby find life in him. Failure to care whether or not loved ones understand the truth is failure to care about their abundant and eternal lives.