People who deny that God exists may give several reasons for their unbelief. For example, they may say they reject God because they can’t understand why He doesn’t do something about all the evil in the world. Or they may say they’re turned off by the hypocrisy of Christians
A.D means in our time (Anno Domini, the year of our lord) and B.C means Before Christ - these two and the other mentioned words are used to B. refer to periods of time.
