You would be very hard-pressed to find a respectable historian who believes that Jesus did not exist. There is arguably more good evidence that Jesus existed than did Alexander the Great. Whether or not he did all the things he is reported to have done is perhaps another matter. The issue of Jesus’ existence, however, is so well established historically, that it is almost never seriously disputed.
We should not influence our children to such a belief or religion. We should just show them the path of goodness; and from that, they can choose according to their interests.