What are some quotes from Friar Laurence that indicate his loyalty to Romeo?

Friar Laurence has a pivotal role in Romeo and Juliet: he marries the couple in secret, he helps Romeo escape to Mantua, and he helps Juliet fake her own death to avoid marrying Paris. It is his plan that goes awry, ultimately resulting in the couples’ deaths; but despite the outcome, Friar Laurence is quite loyal to Romeo.

Friar Laurence hopes that by marrying Romeo and Juliet, he can put an end to the feud between the Montagues and the Capulets:

I’ll thy assistant be

For this alliance may so happy prove

To turn your households’ rancour to pure love (II.ii.90-93)

Still, his loyalty to Romeo extends beyond their union. In Act 2, Scene 2, we can see that he has been giving Romeo advice about Rosaline:

Romeo: Thou chidd’st me oft for loving Rosaline

Friar Laurence: For doting, not for loving, pupil mine (II.ii.181-82)

This shows that Romeo is comfortable confiding in Friar Laurence, and the affectionate term “pupil” suggests a close relationship. After Romeo is banished, the Friar hides him (against the Prince's orders) and encourages him not to despair: 

What, rouse thee, man! thy Juliet is alive,

For whose dear sake thou wast but lately dead (III.iii.134-35)

Friar Laurence comes up with a plan to save Romeo and reunite him with Juliet. Obviously, it goes wrong (the Friar is in many ways an earthly, bumbling character, despite his title), but his intentions are good:

But look thou stay not till the watch be set,
For then thou canst not pass to Mantua;
Where thou shalt live, till we can find a time
To blaze your marriage, reconcile your friends,
Beg pardon of the prince, and call thee back (III.iii.147-151)

At Friar Laurence’s suggestion, Romeo flees for Mantua, while the Friar promises to beg pardon from the prince on his behalf. While Romeo is away, he tries to help Juliet get out of her engagement to Paris. In Act 4, Scene 1 he tries to dissuade Paris from marrying Juliet:

You say you do not know the lady's mind?
Uneven is the course. I like it not (IV.i.4-5)

When Paris proves himself determined, the Friar helps Juliet escape by faking her own death:

Take thou this vial, being then in bed,
And this distilled liquor drink thou off;
When presently through all thy veins shall run
A cold… (IV.i.93-96)

He sends a letter to Romeo explaining the circumstances, but the letter carrier, Friar John, is delayed. Realizing the mistake, he goes to the Capulet family tomb to retrieve Juliet, but Romeo is already dead.

When his plan ultimately goes wrong, his guilt and sadness are evident:

If aught in this
Miscarried by my fault, let my old life
Be sacrificed… (V.iii.265-67)

His (presumably) long relationship with Romeo, his instrumental role in Romeo and Juliet’s marriage, and his good intentions in spite of the outcome show Friar Laurence’s loyalty to Romeo throughout the play. 

Source: Shakespeare, William. “Romeo and Juliet.” The Norton Shakespeare: Tragedies. 2nd ed. Eds Stephen Greenblatt et al. New York, NY: W. W. Norton & Company, Inc., 2006. 189-256. Print.