The old system under the law of Moses was only a shadow, a dim preview of the good things to come, not the good things themselves. The sacrifices under that system were repeated again and again, year after year, but they were never able to provide perfect cleansing for those who came to worship. If they could have provided perfect cleansing, the sacrifices would have stopped, for the worshipers would have been purified once for all time, and their feelings of guilt would have disappeared.
Under the old covenant, the priest stands and ministers before the altar day after day, offering the same sacrifices again and again, which can never take away sins. But our High Priest offered himself to God as a single sacrifice for sins, good for all time. Then he sat down in the place of honor at God’s right hand. There he waits until his enemies are humbled and made a footstool under his feet. For by that one offering he forever made perfect those who are being made holy.
And the Holy Spirit also testifies that this is so. For he says,
“This is the new covenant I will make with my people on that day, says the Lord: I will put my laws in their hearts, and I will write them on their minds.”
Hebrews 10:1-2, 11-16 New Living Translation (NLT)
God does not change. He is the same yesterday, today and forever. However He, who is our Creator, is able to change us. From the old covenant He made through Moses to the new covenant He made through Jesus, God is working to perfect all His hands have made. He sent His perfect Son to die for us and to live within us so that His laws could indelibly be written inside of us as we allow His entrance into our beings. The enemy of our souls cannot erase what God has written on our hearts and minds when Christ lives within us.
The new covenant ensures that Satan's efforts to snatch us away from our Heavenly Father are now in vain and one day his attempts to steal, kill and destroy will stop completely. Jesus is not just some good guy who walked around the earth. He is the very power of God who has been given all authority. He is God's plan to redeem the world and restore it to what He had in mind when He first spoke it into existence and proclaimed it "Good." God does not change and He will not allow His plan to change either.
As we are filled with the Holy Spirit, there is no room for anything inside of us that is not of God. And God has made things new for the sake of our restoration to His original plan.
By calling this covenant “new,” he has made the first one obsolete; and what is obsolete and outdated will soon disappear. Hebrews 8:13 NIV