Ezekiel 3:18-21
King James Version
18 When I say unto the wicked, Thou shalt surely die; and thou givest him not warning, nor speakest to warn the wicked from his wicked way, to save his life; the same wicked man shall die in his iniquity; but his blood will I require at thine hand.

19 Yet if thou warn the wicked, and he turn not from his wickedness, nor from his wicked way, he shall die in his iniquity; but thou hast delivered thy soul.

If you know you must try to share with those who do not know the truth.