That Plan is for us to be joint heirs with Christ. Adopted into His family. Ambassadors for His cause. Why and for what purpose is unknown.
Eph 2:5-10 even when we were dead in our trespasses, made us alive ... and raised us up with him and seated us with him in the heavenly places...so that in the coming ages he might show the immeasurable riches ...toward us in Christ Jesus. For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast. For we are his workmanship, created in Christ Jesus for good works, which God prepared beforehand, that we should walk in them.