Do not deceive or be faithless even with your enemy.

Even if my fellow man has proven faithless time after time, I can at least retain a hope that he will improve, pray for him, and think kindly without frustration and disappointment.

Cynicism stems from disappointment. Cynical and faithless people were not always like that. They were filled with possibilities and hope as kids. But they tried and perhaps failed.

Aragorn: Let the Lord of the Black Land come forth! Let justice be done upon him!
The Mouth of Sauron: My master, Sauron the Great, bids thee welcome. Is there any in this rout with authority to treat with me?
Gandalf: We do not come to treat with Sauron, faithless and accursed. Tell your master this: the armies of Mordor must
disband. He is to depart these lands, never to return.
The Mouth of Sauron: Ahh, old Greybeard. I have a token I was bidden to show thee.
[Pulls out Frodo's mithril vest and throws it at them]
Pippin: [whispers] Frodo...
Gandalf: Silence.
Merry: No!
Gandalf: Silence!
The Mouth of Sauron: The halfling was dear to thee, I see. Know that he suffered greatly at the hands of his host. Who would've thought one so small could endure so much pain? And he did, Gandalf, he did.
[pause; Aragorn rides towards the Mouth of Sauron]
The Mouth of Sauron: And who is this? Isildur's heir? It takes more to make a King that a
broken Elvish blade...
[Aragorn cuts off the Mouth of Sauron's head with one stroke of Anduril]
Gimli: I guess that concludes negotiations.
Aragorn: [to Gandalf] I do not believe it! I will not!

Dain: Good morning. How are we all? I have a wee proposition, if you don't mind giving me a few moments of your time. Would you consider... JUST SODDING OFF! All ye, right now!
Bard: Stand fast!
Gandalf: Come now, Lord Dain.
Dain: Gandalf the Grey. Tell this rabble to leave or I'll water the ground with their
blood.
Gandalf: There is no need for war between Dwarves, Men, and Elves. A legion of Orcs march on the mountain. Stand your army down.
Dain: I will not stand down before any elf! Not least this faithless Woodland sprite! He wishes nothing but ill upon my people! If he chooses to stand between me and my kin, I'll split his pretty head open! See if
he's still smirking then!
Thranduil: He's clearly mad like his cousin.
Dain: Ya hear that, lads? We're on! Let's give these bastards a good hammering!

Demon: Your mother sucks cocks in Hell, Karras, you faithless slime.

Confidante: They say that this youth has set my lady's heart aflame!
Fop #1: His lordship sure would die of shock!
Fop: His lordship is a laughingstock!
Confidante: Should he suspect her, God protect her...
Confidante, Fop #1, Fop: ...shame,
shame, shame! This faithless lady's bound for Hades... shame, shame, shame!

Confidante: [singing] They say that this youth has set my lady's heart aflame!
Fop #1: [singing] His lordship sure would die of shock!
Fop: [singing] His lordship is a laughingstock!
Confidante: [singing] Should he suspect her, God protect her...
Fop
#1, Fop, Confidante: [all three singing in unison] ... shame, shame, shame!
Fop #1, Fop, Confidante: [all three singing in unison] This faithless lady's bound for Hades...
Fop #1, Fop, Confidante: [all three
singing in unison] ... shame, shame, shame!