the Two Natures of Christ
Jesus Christ, the Son of God, Second Person of the Holy Trinity
has two natures: the Divine Nature and his human nature.
His human nature is like us in all things but sin. His human nature has a human body and a human soul. His soul requires grace, both sanctifying grace (habitual grace) and actual grace. He souls received grace directly from His Divine Nature, for the two natures are intimately united as one Person.
This very close and thorough unity, called the hypostatic union, in no way detracts from either nature. His human nature is no less human for being united to his Divine Nature. And the two natures, though not separate, remain distinct.
Jesus was unable to commit personal sin because the two natures are united as one Person. He also did not have original sin, because there can be no sin or fault in a human nature united to the Divine Nature, and because Mary did not have original sin to pass on to her Son.
Since Jesus has two natures, He also has two wills, human and Divine, and two minds, human and Divine. But these two are in perfect harmony, except that all that is human in Christ is finite, and all that is Divine is infinite.
Roman Catholic theologian