Lewis and Clark were determined to find a passage to the Northwest. In order to do that, they had to find a way to cross the Rocky mountains. With determination, planning, and true grit, they crossed the Rocky mountains, and blazed a trail to the West.
The ark of the covenant contained the law of God. Two cherubim guarded the law, with their wings outstretched. They guarded the way to heaven. They continued the watch of the angel with the flaming sword in Genesis 3. This barrier to humanity was even more terrifying and impossible than crossing the Rocky mountains. What we need is a trailblazer. We can follow where someone else leads. Jesus is therefore our Pioneer. He has crossed the barrier into the Most Holy Place. Only He did not need to sacrifice for Himself, since He was perfect. He could therefore cross over into the heavens, opening the way for us.
The way He did this was to make us His siblings. The only way into the Most Holy Place is to be related to Jesus Christ by new birth. He accomplished this by being made perfect in suffering. Now, this does not mean that anything about Jesus the Person was perfected. It means that, as High Priest, he was perfected as to His office. He had fulfilled all righteousness.
And so, in being made perfect, Jesus sanctifies us, proving that we are indeed of one family. It is our kinship to Christ that is emphasized here above all else. Jesus is not ashamed to call us His brothers and sisters. Are we ashamed to acknowledge Him before the world?