Is your question refering to the way that Tom has to learn some verses from the Bible in this chapter? This amusing chapter begins as Aunt Polly starts the time of family worship after breakfast. As part of this time, Tom has to recite the verses that he has learned in front of the family to show how hard he has been working on them.
Tom bent all his energies to the memorising of five verses, and eh chose part of the Sermon on the Mount, because he could find no verses that were shorter. At the end of half an hour Tom had a vague and general idea of his lesson, but no more, for his mind was traversing the whole field of human thought, and his hands were busy with distracting recreations.
The stuttering response that he gives when asked to recite the verses and his attitude towards learning the Bible clearly shows that to Tom, religion is something of an irrelevance. Ironically, he shows that he is able to learn the Bible verses, but only after Mary has promised him "something nice" as a reward if he can learn them quickly. This makes him exert himself and he learns the verses in record time, clearly indicating that he is interested in the Bible only as a source of what he can extract from it.