From a favourite blog. Union with Christ is the central thought in Calvin, and also in Scripture's understanding of the cross and resurrection.
“He is the fountain which never dries up” by John Calvin:
“We should be satisfied with the benefits of our Lord Jesus Christ, and that when we are grafted into His body and made one with Him by belief of the gospel, then we may assure ourselves that He is the fountain which never dries up, nor can ever become exhausted, and that in Him we have all variety of good things, and all perfection.”
–John Calvin, Sermons on Ephesians (Carlisle, PA: Banner of Truth, 1974), 355.