Jesus did many things on our behalf, but I want to emphasize three things he did that are for eternity. These eternal promises are ours in the New Covenant. Hebrews discusses them, but they are mentioned in other scriptures.
Hebrews 9:11- 15 But when Christ came as high priest of the good things that are now already here, he went through the greater and more perfect tabernacle that is not made with human hands, that is to say, is not a part of this creation. He did not enter by means of the blood of goats and calves; but he entered the Most Holy Place once for all by his own blood, thus obtaining eternal redemption. The blood of goats and bulls and the ashes of a heifer sprinkled on those who are ceremonially unclean sanctify them so that they are outwardly clean. How much more, then, will the blood of Christ, who through the eternal Spirit offered himself unblemished to God, cleanse our consciences from acts that lead to death, so that we may serve the living God!
For this reason Christ is the mediator of a new covenant, that those who are called may receive the promised eternal inheritance—now that he has died as a ransom to set them free from the sins committed under the first covenant.
First, eternal redemption is done through Jesus work and promised to us. This kind of redemption is almost like a slave being purchased then taken out of the market never to be purchased again.
Ephesians 1:13-15
And you also were included in Christ when you heard the message of truth, the gospel of your salvation. When you believed, you were marked in him with a seal, the promised Holy Spirit, who is a deposit guaranteeing our inheritance until the redemption of those who are God’s possession—to the praise of his glory. For this reason, ever since I heard about your faith in the Lord Jesus and your love for all God’s people.
Second, not only did Jesus do his marvelous work for us in the past, he is still working on our behalf today because he never stops cleansing us.
1 John 1:9
If we confess our sins, he is faithful and just, and will forgive us our sins, and cleanse us from all unrighteousness.
Third, Jesus gives us eternal consolation and encouragement. God's good grace is there whenever we need it forever! His strength is available to us anytime or place. All we need to do is realize what has been done on our behalf.
2 Thessalonians 2:16-17
God our Father loved us and by his kindness gave us everlasting encouragement and good hope. Together with our Lord Jesus Christ, may he encourage and strengthen you to do and say everything that is good.