When Romeo approaches Juliet and they speak in a sonnet, the language and images which they use are associated with holiness. I need three examples of quotes that show as such, and what are these images supposed to reflect?

In Act I, Scene 5, Romeo approaches Juliet with the teasing statement that if he should "profane" with his "unworthiest hand," the "holy shrine" of Juliet's body, he will be fined for his transgression. The fine will be paid in kisses by Romeo's lips, "two blushing pilgrims." This is extremely forward of Romeo, but the imagery calls to mind the behavior of pilgrims approaching the shrine of a beloved saint. This was common at this point in time, and it was also common for pilgrims' to harm the shrines in their religious fervor, and receive fines. Of course, in this instance, Romeo will not really suffer if the "pilgrims" of his lips have to pay a fine in kisses.
Juliet responds in kind, but suggests that Romeo has not considered the part his hand might play in this pageant instead: "For saints have hands that pilgrims' hands do touch / And palm to palm is holy palmers' kiss." She is saying that in fact, it would be more fitting to Romeo's scenario if he were to express his devotion as pilgrims do, by putting his hands together in prayer and expressing devotion in that way; here she is backing away, albeit teasingly, from his suggestion that any kissing might be necessary. When Romeo asks if pilgrims and saints do not also have lips, she chides him, "Lips that they must use in prayer." (Effectively: if you want to apologize to me or woo me, you must do it with your words. As pilgrims should pray to their saints, Romeo should charm Juliet with words if he wishes to receive her favor.)
Ultimately, of course, Juliet retreats from this and allows Romeo to both "purge" and then take back his sin from her lips, the religious allegory forgotten.