The term “theosis” has two meanings, the condition or the state of deity and the deification of man. Only God has the condition of deity in and of Himself. No man can ever attain true divinity. There is only one God and we are not Him. However, theosis is also the state of being divinized or God-infused, both in character and person (2 Peter 1:4). Peter describes Christians as being “partakers of the divine nature” (KJV). The Greek word koinōnos translated “partakers,” means a sharer, associate, companion. Christians, through the great promises of salvation, sanctification and the privilege of sonship through faith in Christ, become participants in the divine nature of God.
Through the process of theosis, man exhibits or reveals within himself the presence of God in his life. Theosis is also associated with another term called”perichoresis” which is a Greek term describing the relationship between each person of the Trinity. Therefore, theosis is related to his ability for perichoresis, or interrelationship, in which God resides within His human creation. As a result of theosis, and this indwelling relationship of God, man is made alive, full, and complete.
It is only because God created man with the ability to experience theosis, i.e., God literally dwelling within us, that we become a reflection of Him. Another way to look at the idea of theosis is what Paul tells us in Romans 12:2: “Do not conform any longer to the pattern of this world, but be transformed by the renewing of your mind.” Theosis, that process of becoming like God, is the transformation that takes place within the believer. But it is really more than that. This transformation is made perfect through our partaking in His nature through the Holy Spirit which resides within us. As a result, there comes to the Christian a profound sense of unity with God. Though we know that the full realization of our oneness—our perfection with God—comes after death, this process of theosis or divinization grows in time, by degrees, throughout our lives.
One of the best ways to describe how we can become like God is found in the teachings of Jesus, especially in the Beatitudes as recorded in Matthew chapter 5. It is here that Jesus culminates his teachings with the command to be “perfect” as God is. Prior to this, He was setting a new standard, a new law that superseded that of the old law. The goal, to be perfect, to achieve spiritual excellence, is a constant process. The goal for the Christian is essentially to be different from the world, to be more like God.
Having said that, though, it is crucial to understand that we do not experience theosis by any amount of determination or fleshly effort of our own. It is only through the indwelling Holy Spirit, who empowers us and leads us to godly living by His work in our hearts that we can come closer to God and display the divine nature. For example, it is through this process of theosis, becoming one with God, experiencing His absolute, limitless love that we come to know how to love even our enemies. It is only through His Spirit residing within us that we as believers love and pray for those who seek to do us harm (Romans 12:14–21).
 Got Questions Ministries. (2010). Got Questions? Bible Questions Answered. Bellingham, WA: Logos Bible Software.