The 5 Darknesses And Their Lamps
Abu Bakr would constantly remind people of the Truth in person and from the pulpit during his khutba's (sermons). He kept his speeches brief so as not to bore the audience, yet he managed to provide people with important reminders, a wealth of beneficial information and food for thought.
Once he said (and this was his entire khutba):
"There are 5 dark matters and 5 lamps to illuminate them:"
1. Love of this world is darkness, and Taqwa is it's lamp.
2. Sin is darkness, and it's lamp is repentance.
3. The grave is darkness, and it's lamp is the phrase, 'Ash hadu ana la ilaha ila Allah we ash hadu ana Muhammad ar-rasoul allah' 'I bear witness that there is no God but Allah and Muhammad is the Messenger of Allah'
4. The Hereafter is darkness, and it's lamp is good deeds.
5. The Siraat (the bridge over Hellfire which every person will have to cross in the Hereafter) is darkness, and it's lamp is certainty of Faith.