One of the most important insights of Reformed theology is the unity of the works of the Trinity. Calvinists believe that God the Father, God the Son, and God the Holy Spirit are united in the work of redeeming lost mankind. We do not believe that they act against
one another or even on
one another, but with
one another in our salvation. For instance, Jesus did not die to convince the Father to change His attitude toward us from enmity to love. Rather, Jesus died on the cross because of the Father's love for us, as John 3:16 says: "For God so loved the world that he gave his only Son, that whoever believes in him should not perish but have eternal life." The Father and Son are united in their work for the salvation of those who believe: the Father electing and sending His Son; the Son atoning for the sins of those chosen and given to Him by the Father (John 6:37–40). The same harmony exists between the Son and the Spirit. Jesus did not die for the sins of all people, only to have the Holy Spirit apply the benefits of His work merely to some. Rather, the Holy Spirit regenerates precisely the people for whom Jesus offered His atoning death, so that the work of the second and third persons of the Trinity harmonizes perfectly.