That is why the Church baptises babies.
So what do you think happens to the person who dies as an infant if they have not been baptised?
Just to let you know, he and I will have slightly different answers on that one. The CORRECT answer is "no one knows for sure" but we have different theories, with different levels of support for belief. It is not exactly crucial to the faith.
I believe what I was taught as a child - that they go to Limbo (which is not a bad place, in fact it is just like heaven except God is not there.) Then on Judgement Day they will be judged just like everyone else and would most likely go to Heaven since they didn't live long enough to sin.
What do YOU think happens to babies who die before the age of reason?