Donald Bloesch says:

It is interesting to compare Calvin and Barth on this subject. Calvin too sees Christ as the Mediator even before his condescension in human form. He too sees Jesus Christ as containing within himself everything that will be ours in a future redemption. He too believes that Christ had accomplished everything necessary for our salvation, that his sacrifice was definitive and complete. He can even declare that in the death of Christ we have “the complete fulfillment of salvation” and that we “have been born anew” through the resurrection of Christ. Both theologians understand divine election to precede the decision of faith and even the fall of man; yet Calvin is more emphatic than Barth that God’s electing grace will invariably give rise to faith. In Calvin’s view those who benefit from the election and atonement of Christ are the elect people of God, the community of the faithful. For Barth the benefits of the atonement extend to all, though not all apprehend or perceive. For Calvin, Christ is the mediator of the eternal decree of election; whereas for Barth, Christ is both the Elector and the Elected One, who includes within himself the totality of mankind. For Calvin, predestination realizes its goal only in the response of faith; whereas for Barth, predestination has reached its goal in Jesus Christ, though its reality and efficacy are not yet manifest in all those who belong to him. For Calvin, personal faith is the instrument or means by which divine election and justification are effected in the lives of men; for Barth, faith is more properly a revelatory sign and consequence of our election and salvation. Although Calvin seeks to make predestination correlative with faith, both men betray a decidedly objectivistic bent, since the decree of predestination is enacted and completed in the eternal counsel of God, though they both insist that what has been decreed must be worked out and made manifest in history. Barth in trying to underline the dynamic character of predestination can even say that though it is a “completed work . . . it is not an exhausted work, a work which is behind us. On the contrary, it is a work which still takes place in all its fullness today.”

While both theologians maintain that the Christian can have assurance of his election and salvation, Barth’s position that we can be certain only of Christ’s faithfulness to us but not of our faithfulness to Christ tends to conflict with the Calvinist doctrine of eternal security. Barth would never say, however, that people can fall out of the sphere of God’s grace and goodness, though he does affirm the ever-present but incomprehensible possibility of fall away from the path marked out by grace.

The crucial difference between the two men is that Calvin adheres to particular election and redemption while Barth affirms the universality and all-inclusiveness of the electing and reconciling work of God. The doctrine of “limited atonement,” a hallmark of Calvinist orthodoxy, is definitely contradicted by Barth, and here can be seen his affinity to Luther and Wesley. In Calvin all is of grace, but grace is not for all. In Luther and Wesley all is of grace and grace is for all, but not all are for grace. In Barth grace is the source of all creaturely being and goes out to all, but every man is set against grace. Yet every man is caught up in the movement of grace even in the case where there is continued opposition to Christ. At the same time those who defy grace are claimed by grace and remain objects of grace despite their contumacy and folly. The act of turning away from grace is for Barth impossible and it would seem an impermanent condition, since no man can escape from or overturn the all-embracing love and grace of a sovereign God. (Donald Bloesch, “Jesus Is Victor!: Karl Barth’s Doctrine of Salvation,” 70-71)