Final answer:
The implied context behind the question about hymnals for Cal's church suggests that there is hypocrisy in the congregation's behavior. The purchase of hymnals would thus be pointless, as the problem is not with the absence of hymnals but with the actions of the churchgoers themselves.
Step-by-step explanation:
The question seems to reference a specific context such as a novel or a story where hymnals might not be practical for Cal's church. By analyzing the given lines, it seems that even though the community engages in religious activities like reading and singing sacred songs, there is an underlying issue of hypocrisy ('teach the right and do the wrong'). This suggests that the acquisition of hymnals would be futile since the real problem lies within the congregation's behavior, not in the lack of religious materials. They appear to project a superficial image of unity and devoutness ('words of heavenly union'), while their actions contradict their teachings, hence implying that hymnals would do no good for the improvement of their morals or practices.