On the Goodness of God

I used to be a Christian, by that I mean, really believed and actively practiced my faith. I truly accepted Jesus Christ as my Lord and saviour, I ran Bible studies, took kids to and ran kids clubs, led sunday school lessons, ran Alpha sessions, led a house group, attended weeks of prayer and more. I wasn't messing around. So why did I give it all up? I had a lot of questions that I was often too scared to ask, because I felt if I asked them it would show my inability to continue running the activities I ran. I also kind of shot myself in the foot because when non believers asked me questions and I gave them answers, they never followed up with the questions I had in my head, the questions I myself was too scared to ask, so I never aired my questions. So what we're the questions?
I guess that they all boil down to one major question: How do we know God is good? Christians believe Jesus is the son of God and they believe that because, according to the Bible, he was without sin. It also follows (according to mainstream Christianity) that Jesus is also God. We can therefore conclude that God is without sin, He is morally pure. So does God stand up to moral scrutiny? It appears not. when Herod had his authority threatened by the birth of Jesus he gave orders for infanticide to ensure the death of this newborn king of kings. This is an awful event in history, that a person should order the slaughter of hundreds of children to protect his authority. Herod's behaviour is morally wrong. We can conclude that Herod is not God (bear with me). When Pharaoh refused to let God's people go after being ordered to by God, through Moses as a messenger, God decided that action must be taken. God's authority was in danger, he was being challenged. God's final action was to order the killing of the first born children in Egypt. Yes, there was a get out clause, the blood above the door, but none the less he ordered the killing of Children, and sure enough Children died. What makes this worse is that God hardened Pharaoh's heart, he forced Pharaoh's hand, God knew that Pharaoh could not say 'I will let your people go.' God was killing those children no matter what. We can therefore conclude that God is not morally pure. That means that God is not really God, he is not who he claims to be. Now I'm fairly certain this is not a water tight argument, but as yet I have not heard a rational response.
I really want an answer to this question. I don't want to hear silly answers that don't make sense. For example : "God is good, we don't understand his reasons for everything" This ignores the question, how do we know he's good? "God is beyond our understanding and he does things for reasons we can't comprehend." Again this answer makes no sense if he is beyond our understanding how can we understand anything about him, where is the line of understanding drawn? It's a cop out to say this because as soon as we get to something we can't explain we just say "that's because God is beyond our understanding." "Satan has blinded you." if this is the case that means Satan hasn't blinded you so please answer the question for the sake of those who have been blinded. "the very fact you are talking about God, proves there is a God." we can talk about a lot of things that don't exist... There are more but please try and analyse any responses and see if they make sense. I look forward to your response, let's try and dig down into the truth.

Click HERE to read Dr. Craig's response