Please read the passage before reading the commentary.
The author of the letter to the Hebrews says that the one who consecrates, and the ones consecrated share the same nature. Christ consecrates us and calls us brothers (and sisters) (2:11). Therefore, Christ has to share our nature because he consecrates us. The author is not speaking of angels, but of people. People consecrate other people. For God to consecrate us, God has to be one of us and so share our human nature. The author offers no proof for this but seems to accept it as a fact.
This shows us how much God loves us. To consecrate us, God had to have a human nature because God could not accomplish this plan unless God had a human nature. Christ therefore has both a divine and a human nature.
On the other hand, if Christ is God and took on a human nature so that he could share our nature, it is also true that we are sharing Christ’s divine nature since the one who consecrates that those consecrated must share the same nature. Therefore, we have a share in the divine nature of Christ.
This is what we believe about baptism. In Baptism, Christ makes us into his body. If we are baptized into his body, we must be sharing his divine nature somehow or other. This is also what we believe about the Eucharist, that we who are the body of Christ feast on the body of Chrit and so become more so the body of Christ.
Christ, our high priest, learned in a human way how to be a merciful and faithful high priest before God. Christ was tested as we are being tested even now. Because Christ shares the same nature we have and because Christ, shared the same testing we have, Christ can relate to our testing in a merciful and compassionate way.
Christ’s work to save us depends on his sharing our human nature. Our response to Christ depends on our sharing his divine nature. This teaching is not new, but it may help us sustain our faithfulness to God when we remember that Christ is compassionate, understanding, and saving because he shares our human nature with us. We are part of the adventures of Christ our high priest.