This question starts with Psalms 8:5 as a prophecy on the coming Messiah, fulfilled in the New Testament at the coming of Christ, and is repeated almost verbatim by the Author of Hebrews.

Hebrews 2:6-8a It has been testified somewhere, “What is man, that you are mindful of him, or the son of man, that you care for him? You made him for a little while lower than the angels; you have crowned him with glory and honor, putting everything in subjection under his feet.”

We know that Jesus was often called the “Son of Man” (John 8:28, Daniel 7:13, 1 Timothy 2:5), just as He is also the second part of the Trinitarian God-head (John 10:30, Colossians 2:9, Titus 2:13). While on earth, He got tired, He got emotional, He ate food, He was not omniscient (Matthew 24:36), and He had many other attributes of mankind, other than a sinful nature. So, how can Christ be both fully God and fully man (John 1:14, Philippians 2:7, 2 Corinthians 8:9)? If you want to go deep (which is reserved for theologians and totally unnecessary), the term is “hypostatic union,” or the dual nature of Jesus.

Why did Jesus have to be fully God and fully man?

Christ had to be fully God because the Bible makes it clear that all of humanity have sinned …

Romans 3:10-12 - None is righteous, no, not one; no one understands; no one seeks for God. All have turned aside; together they have become worthless; no one does good, not even one.

And, as such, no one can escape eternal death when we are faced with payment for our bad behavior before a righteous God.

Romans 3:23 - For all have sinned and fall short of the glory of God,

Only God (in the form of Jesus) could live a perfect, sinless life amongst the temptations of this world.

At the same time, however, Jesus, the man, had to struggle with those temptations from Satan, who offered Christ the world (Luke 4:6). Also, human weakness was evidenced, for example, prior to His arrest and crucifixion when Jesus asked God to take away what was about to happen (Luke 22:42).

Hebrews 2:17 - Therefore he had to be made like his brothers in every respect, so that he might become a merciful and faithful high priest in the service of God, to make propitiation [appeasement] for the sins of the people.

A Little Lower than the Angels

Jesus was fully God and fully man, and, as noted above, at times He was speaking as part of the God-head, and at other times He was speaking as a man. In Hebrews 2:6-8, the Author was referring to Jesus, from the perspective of a man. Today, this same Jesus is “much superior to the angels” (Hebrews 1:4-5), and humanity remains “lower than the angels.” They are more powerful than mankind, “having supernatural powers and direct access to the throne of God while not being subject to death” (MacArthur Study Bible). However, a day will come when born-again believers with glorified bodies (Philippians 3:21) will also be higher than the angels (1 Corinthians 6:3).

Keep in mind that, for the short time Christ Jesus was on earth, His humanity in no way diminished His deity. “Jesus never ceased to be God; He simply showed the meekness and condescension of God [to His people] … Ultimately, the paradox of Jesus being fully God and fully man calls us to a deeper faith in the wisdom of God.”