The Reasonable Faith Podcast with Dr. William Lane Craig is in my opinion the best apologetics podcast on the internet.
Dr. Craig deals with timely issues in an easy to understand manner without dodging the tough questions. Further, he addresses numerous topics that repeatedly come up when one is sharing his faith.
One such objection (or supposed dilemma) is the the Euthyphro Dilemma. The name Euthyphro refers back to a famous dialog written by Plato between Socrates and Euthyphro. In this interaction, Socrates is attempting to understand the essence of piety and holiness.
Socrates: And what do you say of piety, Euthyphro? Is not piety, according to your definition, loved by all the gods?
Socrates: Because it is pious or holy, or for some other reason?
Euthyphro: No, that is the reason.
Socrates: It is loved because it is holy, not holy because it is loved?
Apologist Greg Koukl explains the dilemma Euthyphro faced here:
"Is a thing good simply because the gods say it is? Or do the gods say a thing is good because of some other quality it has? If so, what is that quality?" 
Koukl goes on to point out how in recent times, Plato's approach has been used as an assault of sorts on the coherence of Christianity. In Bertrand Russell's Why I Am Not a Christian, Russell presents the problem this way:
"If you are quite sure there is a difference between right and wrong, you are then in this situation: Is that difference due to God's fiat or is it not? If it is due to God's fiat, then for God Himself there is no difference between right and wrong, and it is no longer a significant statement to say that God is good. If you are going to say, as theologians do, that God is good, you must then say that right and wrong have some meaning which is independent of God's fiat, because God's fiats are good and not good independently of the mere fact that he made them. If you are going to say that, you will then have to say that it is not only through God that right and wrong came into being, but that they are in their essence logically anterior to God." 
So, in summary, Russell is basically asking, "Is a thing right simply because God declares it so, or does God say it is good because He recognizes a moral code superior even to Him?
In the following two podcasts, Dr. Craig takes a look at this so-called dilemma and demonstrates how:
- Objective Morality is Grounded in God
- Euthyphro's Dilemma is actually a false one
Finally, I would recommend Greg Koukl's article Euthyphro's Dilemma.
Courage and Godspeed,
1. Greg Koukl, Euthyphro's Dilemma, http://www.str.org/site/News2?page=NewsArticle&id=5236, 2002.
2. Greg Koukl, Ibid.