Kenosis is a Greek word for emptiness, which is used as a theological term.
As an ancient Greek word, κένωσις kénōsis means an "emptying", from κενός kenós "empty".
The word is mainly used, however, in a Christian theological context, for example Philippians 2:7, "Jesus made himself nothing (ἐκένωσε ekénōse) ..." (NIV) or "...he emptied himself..." (NRSV), using the verb form κενόω kenóō "to empty".
Kenosis is similar to the Buddhist practice of Shunyata.
An apparent dilemma arises when Christian theology posits a God outside of time and space, who enters into time and space to become human (incarnate). The doctrine of Kenosis attempts to explain what the Son of God chose to give up in terms of his divine attributes, or divinity, in order to assume human nature. Since the incarnate Jesus is simultaneously fully human and fully divine, Kenosis holds that these changes were temporarily assumed by God in his incarnation, and that when Jesus ascended back into heaven following the resurrection, he fully reassumed all of his original attributes and divinity.
Specifically it refers to attributes of God that are thought to be incompatible with becoming fully human. For example, God's omnipotence, omnipresence, omniscience as well as his aseity, eternity, infinity, impassibility and immutability. Theologians who support this doctrine often appeal to a reading of 5-8. Critics of Kenosis theology argue that the context of Philippians 2:5-8 is referring to Jesus voluntarily taking the form of a servant to conceal his divine glory (revealed temporarily in the Transfiguration), or to forsaking his place and position in heaven to dwell among men, as opposed to forsaking his divine attributes or nature.
Kenotic Christology focuses on certain passages in the Gospels where Jesus does not allow himself to be called good, and evidence that he was not omniscient concerning the date of the Second Advent. It became a central issue in the Protestant debates of the sixteenth century, and was revived in the nineteenth century to reinterpret classical doctrines of the incarnation.
However, theosis never concerns becoming like God in nature or essence, which is pantheism; instead, it concerns becoming united to God by grace, through his Energies. One notices that Orthodox theology distinguishes between divine Essence and Energies. Kenosis therefore is a paradox and a mystery since "emptying onself" in fact fills the person with divine grace and results in union with God.
Another perspective is the idea that God is self-emptying. He poured out himself to create the cosmos and the universe, and everything within it. Therefore, it is our duty to pour out ourselves. (This is similar to C.S. Lewis's statement in Mere Christianity that a painter pours his ideas out in his work, and yet remains quite a distinct being from his painting.) In so doing, we become deified like God. Another term for this process is theosis.