Similarities between life of Pi and Poisonwood Bible?

yes

You can compare the father figures in both. You can compare the magic realism in both. The obvious religious angles-- the white savior trope that plays out in Africa so badly, the salvation learned by relying on a terrible natural foe whose nature you must understand or else perish by. [You can wander into a thread on how Christianity can mirror that relationship between the boy and the tiger on the open seas. Understand the tiger or be devoured by the hyena, or something to that effect.] You can explore how the lives of the sisters and the lives of Pi and Richard Tyler...yeah, there's all kinds of stuff here to explore in both Kingsolver's and Patel's novels.