The first thing to note is that this is part of Barth's doctrine of God. It fits here because for Barth God's gracious election is fundamental to our understanding of who God is. "If it is true, then, that this Subject is disclosed only in the name of Jesus Christ, that it is wholly and entirely disclosed in Him, then we cannot stop at this point, defining and expounding the Subject only in and for itself" (II/2, 5). The God we come to know in Christ cannot be considered apart from his gracious election of a partner without dangerous abstraction from revelation. The only way we know God is through Christ, and so the only God we know is the God who loves in freedom.
There are two main aspects of the election of grace. On the one hand, the word 'grace' tells us that we are dealing with "a divine benefit or favour" (10). More than that, "It is love in the deepest condescension. It occurs even when there is no question of claim or merit on the part of the other. It is love which is overflowing, free, unconstrained, unconditioned" (10). In Jesus Christ, God is gracious. On the other hand, the word 'election' tells us that this involves choice. "First and foremost this means that God makes a self-election in favour of this other" (10). Although having no need of any partner, God wills himself as the partner of another. He chooses this for himself, and therefore he chooses the other. This just underlines the concept of grace: "God owes his grace to no-one, and... no-one can deserve it" (11). If they nevertheless receive it, it is all of God.
Barth is clear that the doctrine of election should be for us a "proclamation of joy", "not a mixed message of joy and terror, salvation and damnation" (13). "It does, of course, throw a shadow" (13), but this shadow does not undermine its character as fundamentally gospel. God has chosen to be the God who is with us and for us, and as such has chosen us for himself. Therefore, "the election of grace is the sum of the gospel" (13). For Barth, the fact that many of the classical expositions of the doctrine (e.g. Augustine and Calvin) have left it with two equal faces shows that they have fallen prey to abstraction and not adhered to the revelation of God in Christ - even though he accepts that it was their intention only to expound that revelation.
There are three concerns which Barth believes lie behind the doctrine. Firstly, the freedom of God. This is "the nerve of the doctrine" (19), and the reason it has always been asserted. God is free in his grace. "Grace cannot be called forth or constrained by any claim or merit, by any existing or future condition, on the part of the creature" (19). When God loves the creature, he does so in freedom.
Secondly, the mystery of God. We cannot pry into God's designs and plans. "We were not admitted to the counsel of God as He made His election, nor can we subsequently call Him to give account" (20). It is the will of God, and that is enough.
Thirdly, the righteousness of God. When we are silenced by God's election, it is not by a brute fact or by force. "It is not that our mouth is stopped... It is rather because our ears have heard the Therefore which is the truly satisfying and convincing answer to every Wherefore" (22). In his election, God himself communicates himself to us, He has "given us Himself as the answer" (22), and if that is not enough for us then we are fools.
Barth suggests that the classical exponents of the doctrine of election, who agree that these are indeed their main three concerns, have fallen into the error of abstraction, and so have not seen the doctrine of election as gospel. They have in some sense sought to go behind the God revealed in Christ in order to see some unrevealed mystery of election driving God's interactions with humanity. This won't do for Barth. "As against that, we must take as our starting point the fact that this divine choice or election is the decision of the divine will which was fulfilled in Jesus Christ, and which has as its goal the sending of the Son of God" (25). In other words, the doctrine of election is the gospel, and is not something that stands in the shadows behind the gospel.
At the end of this sub-section, Barth begins to sketch out what an evangelical doctrine of election ought to look like, in his view. It involves the three points of consensus, but reconfigured, as utterly good news because filled out with the knowledge of Christ. For me, this section is beautiful, and it is interesting to think that what Barth presents as the doctrine of election here fits with what I have been taught in my Calvinist upbringing, with this difference: there is no lurking spectre in Barth, no suggestion that perhaps these things may not apply to us. I'm not sure how to process that yet. But here is an example of the prose:
"If a man has not been allowed to fall by God, then he cannot fall at all, and least of all can he cause himself to fall. God himself in his freedom has decided that he shall stand, that he shall be saved and not lost, that he shall live and not die. He cannot take these things, but they are given to him in the freedom of God... This is the incomparable and inexhaustible blessing visited upon him in the election of God".
And that, as Gandalf might say, is an encouraging thought.