Here, the reader is being told, by now you should be mature in your understanding of Jesus and what it means to place your faith in God. You should know so many things about being a Christian and once you know these things about baptism and laying of hands and the resurrection and eternal judgement, there is more to learn. It is time to continue your education.
4For it is impossible to bring back to repentance those who were once enlightened—those who have experienced the good things of heaven and shared in the Holy Spirit,5who have tasted the goodness of the word of God and the power of the age to come--6and who then turn away from God. It is impossible to bring such people back to repentance; by rejecting the Son of God, they themselves are nailing him to the cross once again and holding him up to public shame.
In the verses above. the author is speaking of true spiritual rebellion, not simply backsliding. Once you are truly saved, born again and know Jesus Christ in your heart, you know all the God that he has to offer. To outright turn your back on that is not the same as just not living a life for Christ. We all fall short of the Glory, but none of us should ever deny the Glory of God.
7When the ground soaks up the falling rain and bears a good crop for the farmer, it has God’s blessing. 8But if a field bears thorns and thistles, it is useless. The farmer will soon condemn that field and burn it.
You have just read a parable of to teach a spiritual and moral lesson to give warning about the possibility of falling away from your faith. The emphasis here is actually on how we must continue to grow in faith and be spiritually productive.
9Dear friends, even though we are talking this way, we really don’t believe it applies to you. We are confident that you are meant for better things, things that come with salvation. 10For God is not unjust. He will not forget how hard you have worked for him and how you have shown your love to him by caring for other believers, as you still do.11Our great desire is that you will keep on loving others as long as life lasts, in order to make certain that what you hope for will come true. 12Then you will not become spiritually dull and indifferent. Instead, you will follow the example of those who are going to inherit God’s promises because of their faith and endurance.
God’s Promises Bring Hope
13For example, there was God’s promise to Abraham. Since there was no one greater to swear by, God took an oath in his own name, saying: 14“I will certainly bless you,
and I will multiply your descendants beyond number.”
15Then Abraham waited patiently, and he received what God had promised.
16Now when people take an oath, they call on someone greater than themselves to hold them to it. And without any question that oath is binding. 17God also bound himself with an oath, so that those who received the promise could be perfectly sure that he would never change his mind.
As you read this, there is a confidence that this message is not about you. You are not guilty of spiritual rebellion or abandoning your faith in God. You are in the word and you remain loyal to Christ. Your hope of eternal salvation is certain because God can not lie and his promises are firm and unwavering
18So God has given both his promise and his oath. These two things are unchangeable because it is impossible for God to lie. Therefore, we who have fled to him for refuge can have great confidence as we hold to the hope that lies before us. 19This hope is a strong and trustworthy anchor for our souls. It leads us through the curtain into God’s inner sanctuary.
God's promise gives us hope that is like an anchor. An anchor holds a ship safely in place. It goes all the way to the depths of the sea just as a Christian anchor goes up into the heights of Heaven, The faithful Christian's life is secured or anchored by God himself.
20Jesus has already gone in there for us. He has become our eternal High Priest in the order of Melchizedek.
The name Melchizedek is mentioned a few times in the Bible. He is our High Priest forever and it is believed that he represents Jesus. It would make sense in Genesis he is referred to as a priest of God and there was none before or after him in the line of Melchizedek.