And having been perfected, He became the author of eternal salvation to all who obey Him,
— Hebrews 5:9

We know that God is perfect, but then why did Christ, who was God, need perfection, to be made perfect? Sometimes we understand imperfection as something defective or sinful that needs work to improve it. In fact, in the Bible perfection means reaching the fullness that God has determined. Christ, being the Son of God, was born in a human body, and having taken on the form of flesh, He needed to be perfected.

He was born a child, so to begin His ministry He had to grow up, to become an adult. In Luke 2:52 we read: “And Jesus increased in wisdom and stature, and in favor with God and men.” “Increased” more precisely means advanced, grew. But isn’t Christ the wisdom and grace of God — why did He need to increase? Jesus is the Word of God, and the Word is like a seed. A seed contains all the properties and all the information of the mature being whose seed it is. In the physical, visible world there is the concept of growth, that is, a certain time is needed for a seed to reach full maturity — or, in biblical terms, perfection.

Paul writes to the Galatians: “Now I say that the heir, as long as he is a child, does not differ at all from a slave, though he is master of all, but is under guardians and stewards until the time appointed by the father.” [Gal.4:1-2] In the same way Jesus, until the time appointed by the Heavenly Father, was subject to His earthly parents. [Luk.2:51] And when the fullness came, when Jesus grew up and reached the age of thirty, “the Holy Spirit descended in bodily form like a dove upon Him, and a voice came from heaven which said, ‘You are My beloved Son; in You I am well pleased.’” [Luk.3:22]

To become our High Priest, the representative of mankind, Jesus also needed to be perfected. It is written that He is a High Priest who can sympathise with our weaknesses, and who was in all points tempted as we are, yet without sin. [Heb.4:15] To be perfected, to become the perfect representative of mankind before God the Father, He had to go through every human suffering. Jesus, it is written, bore our infirmities and sicknesses, and so He experienced the pain and suffering of every sickness, every loss and every curse. So, having gone through all the sufferings of mankind and having been perfected, He became the source of eternal salvation — not only from hell, but from every earthly suffering.