When Christians talk about Jesus, and the atoning sacrifice He made on the cross for our sins, many times this is where they stop. The problem is they leave out the third act to the greatest story in history. His resurrection.
Paul says in 1 Cor 15:14 And if Christ be not risen, then is our preaching vain, and your faith is also vain.
This is where the rubber meets the road.
Everything in the Old Testament, and Jesus’ life, culminates in this grand encore. If one were to study the apostles you can see a massive change in them from pre-cross to post-pentacost. Soon after Jesus’ resurrection they are filled with power from the holy Spirit and boldly preach the Gospel even unto death. Paul promises in Eph 1:13 that after we believe we are sealed with this same holy Spirt.
Believers should be confident not only in our adoption as sons and daughters, but also the inheritance that comes with it. An eternal existence and access to this same power.