humanity of Christ
Jesus Christ as man was in every respect like unto us, except in sin and the consequences of sin.
Christ could not have been mediator between God and men (1 Timothy 2) and the head of humanity, He could not have called Himself "Son of Man," unless He was a true and perfect man.
A complete human nature implies, in the first place, a rational soul.
Christ's soul differed from ours only in the marvelous perfections and graces with which it was enriched.
His human intellect did not possess infinite knowledge which belonged only to His Divine intellect, but it possessed in the highest degree the beatific vision, infused knowledge, and acquired knowledge.
By the first He saw the Divine essence from the first instant of the creation of His human nature; by the second, He knew like the angels by means of infused ideas, without sensible images and reasoning; and by the third He apprehended by means of His senses and reason (Luke, 2).
By making use of the senses and reason Christ learned from experience what He already knew theoretically and supernaturally (Hebrews 5).
Christ possessed not only a human intellect but also a human will: "Father, not my will (human will) but Thine (Divine will) be done" (Luke, 22).
Besides being impeccable, Christ's human will was in perfect conformity to His Divine will, because one and the same Divine Person operated through both.
Christ also had a true and real body and not an imaginary or heavenly body, as certain heretics claimed.
The view of the latter would imply that Christ did not truly suffer and die for us and that He deceived us.
Since Christ's body was conceived miraculously by the supernatural operation of the Holy Ghost, it did not possess those infirmities which flow from sinful fallen nature.
Christ's body was perfect, complete, and becoming His condition.
Being fashioned directly by the Holy Ghost it possessed a beauty worthy of its Divine nature.
Christ assumed only those infirmities which in the present order flow from the natural constitution of the body, such as hunger, thirst, sufferings, and death.
Christ willed to experience bodily suffering in order to expiate our sins and to give us a superlative example of all virtues.
New Catholic Dictionary