Hebrews.
Chapter 6.
So let's not get stuck on the basic teachings about Christ, but let's progress to a more mature understanding. We don't need to go over again the ideas of repenting from what we used to do, about trusting in God— 
or teachings about baptism, the laying on of hands, the resurrection of the dead, and eternal judgment. 
So let's get on with it, as God gives us the opportunity! 
It's impossible for those who once understood and experienced God's heavenly gift—who shared in receiving the Holy Spirit, 
who had known God's good word and the power of the coming age— 
and then completely abandon God, for them to be brought back to repentance once more. They themselves have crucified the Son of God all over again and publicly humiliated him. 
Land that has been watered by rain, and produces crops for those who farm it, has God's blessing. 
But land that only produces weeds and thorns is worthless, and is about to be condemned. In the end all that can be done is to burn it. 
But dear friends, we believe better of you and your salvation, even if we talk like this! 
God wouldn't be so unjust as to forget what you've done and the love you've shown for him by the care you've shown for fellow-believers—something you're still doing. 
We want each of you to show the same kind of commitment, confident in God's hope until it's fulfilled. 
Don't be spiritually lazy, but follow the example of those who through trusting in God and patience inherit what God has promised. 
When God gave his promise to Abraham he could swear by no one greater so he took an oath on himself, 
saying, “I will definitely bless you, and multiply your descendants.” 
And so, after patiently waiting, Abraham received the promise. 
People swear on things that are greater than they are, and when they have some dispute the oath is taken as the final word on the matter. 
That's why God wanted to demonstrate more clearly to those who would inherit the promise that he would never ever change his mind. 
So by these two actions that can't be changed, and since it's impossible for God to lie, we can have total confidence, having run for safety to take hold of the hope God presented to us. 
This hope is our spiritual anchor—it's both certain and reliable, and it takes us past the curtain to the presence of God. 
That's where Jesus went in on our behalf, because he had become a high priest according to the order of Melchizedek. 
