There are many areas of study that people can pursue and most of them end with -logy which is a combining form “denoting a subject of study or interest.” When the greek word θεός (theos) meaning “divine being,” “true God,” is combined with -logy it forms the word “theology” which has the literal meaning of the “study of God.” This is a basic definition, and many have expanded this definition. Saint Augustine’s basic definition was stated as “rational discussion respecting the deity.” John Frame writes, “theology is the application of scripture, by persons, to every area of life.” David Clark defines evangelical systematic theology as:
The science by which evangelical believers learn of God. It is rooted in the Bible and focused on Christ. Through this knowledge, the spirit transforms us into followers of Christ and forms us into Christian communities, awakening in us the wisdom of God that leads to genuine worship and cultural transformation. Through theology we know and love God.
B.B. Warfield explains that in order to have a “true theology” a harmonious interaction of authority, intellect and heart is needed. The authority of the scriptures supplies the substance for the intellect which lands in the heart, so that life is beautified. The last defining statement belongs to Michael Bird, “theology is something that is learned, lived, sung, preached, and renewed through the dynamic interaction between God and his people.”
Closely related to the definition of theology is the term doctrine which may be defined as a collection of teachings centered on theological topics. Doctrine accentuates the core, authoritative and agreed upon teachings of a community’s faith. Doctrine is the content of a faith community’s distinct conversations about God. Doctrine describes what God is up to in the universe, how he relates to humanity and the inherent implications. God reveals and communicates his intentions, then acts upon and completes his intentions, then tells humanity what he did. These accomplishments are the essence of doctrine. Michael Bird with his emphasis on the gospel explains that doctrine emerges from the gospel, and so the gospel is the foundational teaching and ultimate rule of the Christian faith. It provides the glasses that Christians look through in order to understand God’s salvation and mission for the church.
Therefore, in view of these definitions, it is easy to identify God as the object of theology and doctrine, but God is unlike any other object of study. God is a personally knowable object of study. God is personal and desires to be in relationship with humanity. God has made this possible by revealing himself in the universe and in the scriptures and through the life and ministry of Jesus, the Christ. With this in view, Christians should seek to personally know the object of their faith and to draw near to God in order to experience his glory, holiness and love. They should strive to know Christ and the power of the resurrection. That Christ has died, Christ has risen and Christ will come again!
 https://en.oxforddictionaries.com/definition/-logy  Walter Bauer et al. “θεός,” BDAG 357-358. Augustine, Civ. 8.1 quoted in Michael F. Bird, Evangelical Theology: a Biblical and Systematic Introduction, (Grand Rapids, MI: Zondervan, 2013) EPUB edition, Part 1.1, “What is Theology?”  John M. Frame, Systematic Theology: An Introduction to Christian Belief. (Phillipsburg, NJ: P&R Publishing Company, 2013.), EPUB edition, ch.1 “What is Theology?”  Clark, To Know, xxxii.  B.B. Warfield, “Authority, Intellect, Heart,” Selected Shorter Writings II, 668-671. Bird, Evangelical, Part 1.1, “What is Theology?” G.J. Thompson, “Doctrine,” NDT, EPUB edition.  Karl Barth, Church Dogmatics: The Doctrine of the Word of God. Trans. G.W. Bromiley; London: Continum, 2004 , 1/1:11 cited in Bird, Evangelical, Part 1.1, “What is Theology?”  Horton, Christian, Introduction, Part I. A. “Drama: The Greatest Story Ever Told.”  Bird, Evangelical, Part 1.2, “What Do You Have to Say Before You Say Anything?”