We read this in Genesis 2:1-3:
Thus the heavens and the earth were finished, and all the host of them. And on the seventh day God finished his work that he had done, and he rested on the seventh day from all his work that he had done. So God blessed the seventh day and made it holy, because on it God rested from all his work that he had done in creation.
God’s rest on the seventh day of creation teaches us that His work was perfect and complete. Nothing was lacking, missing or needed altering. Therefore, life for Adam and Eve before the fall was that of completeness, rest and celebration.
In the same way, the Bible also teaches us that God’s work of redemption (re-creation of His fallen creatures) through Christ is perfect and complete. Jesus said, “It is finished” (tetelestai, paid in full, John 19:30), and it is finished indeed. On the cross, He fully paid for sins and perfectly satisfied God’s wrath. In Him, all true Christian believers have perfect, complete and eternal salvation.
When Christ had offered for all time a single sacrifice for sins, he sat down at the right hand of God… For by a single offering he has perfected for all time those who are being sanctified. (Hebrews 10:12,14)
Stop doubting and rejecting Christ. Trust in Him alone for salvation and you will be saved indeed. By the grace of the Holy Spirit, you will live a God-redeemed life of completeness, rest and celebration in Jesus.