Apologetics

I am no good at apologetics. Really, I suck at defending my faith. I believe, and I read the Bible, and I'm bringing up my kids that way, too.

So when I was confronted today by someone who asked me a question, I had no idea what to say. I had to go ask someone else, and look up verses online.

What do you say to an unbeliever who asks: "If your God is so merciful, wouldn't that mean that he would accept everyone into Heaven, and not just those who followed Him?"

I need to take a course on apologetics. Right now I'm reading Mere Christianity by C.S. Lewis - hopefully that will help a little, right?