What are some quotes that show that Friar Laurence is a father figure to Romeo?

Friar Laurence acts as a father figure to Romeo throughout the play. He's a much-needed source of wisdom to the young man, helping the love-struck teenager gain a much broader perspective on life. Romeo has fallen head over heels in love with Juliet, and as we might expect he wants to take their relationship to the next level by marrying her. But the Friar cautions against proceeding too quickly:

Wisely and slow. They stumble that run fast. (act 2, scene 3)

The Friar's wise words are a classic example of dramatic irony, for we know that Romeo will indeed "run fast" and "stumble" in his desire to be with Juliet.
When Romeo is banished from Verona for killing Tybalt, Friar Laurence expects him to be relieved at the news—for he has escaped a death sentence for his crime—or at the very least, grateful. But no. For Romeo, exile is worse than death, because it means being apart from his beloved Juliet. Friar Laurence's response shows that to be a father figure you sometimes need to be speak firmly:

O deadly sin! O rude unthankfulness! Thy fault our law calls death, but the kind Prince, Taking thy part, hath rushed aside the law, And turned that black word “death” to “banishment.” This is dear mercy, and thou seest it not. (act 2, scene 3)

Friar Laurence knows how much Romeo loves Juliet. But he also knows how dangerous love can be, how all-consuming and insane. Too much love too soon is likely to fizzle out before long. So the Friar impresses upon Romeo the need to love moderately:

These violent delights have violent ends And in their triumph die, like fire and powder, Which, as they kiss, consume. The sweetest honey Is loathsome in his own deliciousness And in the taste confounds the appetite. Therefore love moderately. Long love doth so. Too swift arrives as tardy as too slow. (act 2, scene 6)