Martyn Lloyd-Jones
We must stand firm in the truth, in the message, for without it we have no power. We may be very nice and kind to one another, but that will not convince the world of sin, and bring them to Jesus. The truth alone can do that.

Whenever you hear a word from my mouth, you shall give them warning from me. If I say to the wicked, ‘You shall surely die,’ and you give him no warning, nor speak to warn the wicked from his wicked way, in order to save his life, that wicked person shall die for his iniquity, but his blood I will require at your hand.
Ezekiel 3:17b-18