Paul opens his letter to the Thessalonian church with thanksgiving for their faith and the transformation in their lives. They "turned to God from idols... and wait for His son from heaven." We who believe have also been delivered from "the wrath to come" by the work of Jesus.
On this Resurrection Sunday, we celebrate the work of Christ and remember the same elements that Paul points to in the start of this letter. Here Paul brings up these points in reverse chronological order: Christ has ascended to heaven, he rose from the grave, and his death delivered us from God's wrath.
Our faith is rooted in this work of Christ. We celebrate His death because it pays the penalty for our sins. We celbrate His resurrection because it gives proof to His work and ushers in a new life that we also will participate in, and we celebrate his work in heaven and look forward to His future return.
Christ lives. He has delievered us from wrath. He is returning to set all things right.