Summary: We may not realize it, but we all need a guide - someone to take us into the dangerous presence of God. Many of us feel ashamed because of our own failures. But Jesus knows our weaknesses through and through, yet willingly guides us to the Father.
The family in America is changing. Recent statistics show that the "typical" American household no longer mirrors Ozzie and Harriett - with two married people at home with the kids and the dogs and the Beav. The most common household in America now is a single parent. We’ve gotten used to going it alone. It seems as if more and more there is no one in our court, no one to hold our hand or wipe our tears away or guide us through a new and terrifying chapter in our life.
And so we have a hard time imagining the high priesthood of Jesus Christ. In some ways it is like our attorney, our agent, our father, and our teacher - all rolled up into one - and so much more. But for many of us - some of these authority figures carry with them bad memories - so I want you to lay aside what earthly examples of advocates you’ve had, and let the advocacy of a perfect father, teacher, and agent give you comfort you may have never felt before.
This section is really a continuation of the main argument the author of Hebrews has made so far - that Jesus is better than Moses. Chapter 3:7 through verse 13 of chapter 4 is almost a parenthetical thought about entering into the rest of God - but it relates to the main argument as well. At certain points the author points out that Jesus is like the fulfillment of the Jewish system, but then He is also so much more - providing a rest that no one got in the physical Promised Land, and though he is like Aaron the high priest - He can do so much more than Aaron could ever do.
The author has referred to Jesus as our high priest twice before in the book. First in chapter 2 he said:
Hebrews 2:17-18 (quickview)  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 for the sins of the people. 18 For because he himself has suffered when tempted, he is able to help those who are being tempted. ESV
Then in Chapter 3:
Hebrews 3:1-2 (quickview)  Therefore, holy brothers, you who share in a heavenly calling, consider Jesus, the apostle and high priest of our confession, 2 who was faithful to him who appointed him ESV
As we will see - Jesus must be perfect and do exactly what the Father told Him to do - but He is also so much like us that He can take that perfection and bring it down to us humans in need. To understand we need to look briefly at the qualifications and duties of the high priest. Remember - the high priest was appointed by God - Aaron was the first, then his sons after him.
Anointing oil placed on head
Must wear special clothes
Hair "unkempt" clothes in place (not torn)
Must be kept clean (cannot come near dead body)
Must stay in the Sanctuary
Marry a virgin from Israel
No physical deformity or disability
Duties of the high priest on the Day of Atonement:
Put on the special clothes, sacrifice a bull for his sins and his family’s sins, take two goats - one he sacrifices as a sin offering - the other is the scapegoat, upon which all the sins of Israel are laid - then it is set free. To enter the Holy of Holies he takes coals from the altar and mixes them with incense to create smoke that will cover the atonement cover - then he sprinkles the blood of the bull in front of the atonement cover 7 times. Then he kills the goat for a sin offering for the people - and sprinkles it in front of the atonement cover and over the Tent of Meeting to atone for the "rebellion" and "uncleanness" of the people. He is alone when he does this - a process which is repeated for the altar - I’ve left a lot out.