Krebs's mother foreshadows both the climax of the short story and Krebs's inability to pray when discussing the role God has for Krebs:
"God has some work for every one to do," his mother said. "There can be no idle hands in His Kingdom." "I’m not in His Kingdom," Krebs said. "We are all of us in His Kingdom." Krebs felt embarrassed and resentful as always.
Krebs, in asserting he is outside of God's Kingdom, foreshadows his later inability to pray. This inability is further evidence that Krebs is in fact outside of God's Kingdom, although he does say he wants his mother to pray for him, indicating a desire to rejoin the world of man and no longer live a life divorced from other people and from God. Furthermore, the disagreement between Krebs and his mother about Krebs's place in God's kingdom foreshadows the disagreement which serves as the climax of the short story, namely Krebs's lack of love for his mother and the aforementioned inability to pray.
The discussion of God and his Kingdom is, ultimately, a discussion about Krebs finding employment. The conclusion of the story, Krebs resolving to go to Kansas City and find a job, is then also hinted at here, in the initial stages of disagreement.
The role of God's Kingdom in the story is particularly significant given Krebs's life as a soldier, where he was exposed to the darker side of human nature and, presumably, forced to take human lives. As a result of his time as a soldier Krebs feels as if he is outside of God's Kingdom, and yet it is his time as a soldier that Krebs reflects on most fondly. This internal tension separates him from those who did not fight in the war, once more isolating him from his family.