By secular, I am assuming you mean in a home where God is not discussed, nor is a faith practiced.
IMO, children raised without a faith base may have nothing to turn to when they face difficulty making sense of the problems that arise in every life, situations that don't always have worldly solutions or clear answers. They may be raised to be self-sufficient, well mannered, intelligent, well educated, considerate of others, obedient to their parents, but children need something more. It is my observation that children raised in a faith may at some point, question it as something unneccesary and irrelevant, something that was 'forced' upon them by their parents. They may even leave it behind for an extended period of time, but, it is also my experience that at some point in their lives they will return to the faith of their childhood, or seek some faith to join, to feel part of, to belong to when the secular world leaves them completely unsatisfied.
Thinking that children should be allowed to choose for themselves when they come of age is a terrible mistake. We wouldn't withhold a basic education, or health, or dental care from children until they could decide for themselves. Why would we withhold something as fundamental as faith in God?