People spend billions per year on gadgets, programs, vacations and gurus to obtain peace. But peace is a gift only given by God through faith in Jesus Christ. And it is only right that believers, having obtained peace should rejoice.
Romans 5:1-2 Therefore, since we have been justified by faith, we have peace with God through our Lord Jesus Christ. 2 Through him we have also obtained access by faith into this grace in which we stand, and we rejoice in hope of the glory of God.