Matthew 18:5 "Whoever receives one such child in my name receives me, 6 but whoever causes one of these little ones who believe in me to sin, it would be better for him to have a great millstone fastened around his neck and to be drowned in the depth of the sea.
Jesus puts a great deal of value in training the next generation to follow Him. We cause a child who believes in Jesus to sin by what we don't do as well as by what we do. If we don't teach a child the truth, then we are allowing the child's mind to be controlled by the sinful nature (Romans 8:6-8). If we don't live a godly life before a child, then we are modeling how to live a sinful life.
If we do teach a child the truth we are renewing his/her mind and teaching him/her how to be transformed and live according to God's will (Romans 12:2b). If we live a godly life before a child, we are giving him/her a model of godliness to follow. When we live a godly life we are teaching a child to avoid sin.
The consequence for the one causing a little one who believes in Jesus to sin is severe. Jesus states it is better to be drowned in the sea than to cause a little one to sin. We need to take pains to teach the truth to children and to live the truth before children. If we do, the next generation is prepared to follow Jesus. If we don't, we raise a generation that does not live righteously, but does live sinfully.
Let's take the words of Jesus to heart and not cause children to sin by what we aren't doing or by what we are doing.