Jesus said that anybody who welcomes a child into their heart, is welcoming Jesus into their heart, and anybody who welcomes Jesus into their heart, welcomes God into their heart.
The Mark 9:42 New International Version Bible Says:
“If anyone causes one of these little ones—those who believe in me—to stumble, it would be better for them if a large millstone were hung around their neck and they were thrown into the sea.”
The way I understand that verse is that God expects you to take care of the emotional needs and interests of children, and respect the fact that they are not as strong or as competent as mature adults. So you should help the 4 year old find his lost teddy bear, in the same way you visit the 80 year old who is dying of cancer at the hospital, and not act like the 4 year old is silly and stupid for caring about an inanimate object that cannot speak or breath, to acknowledge the emotions of the infant, even if they are trivial and silly and foolish, and to hug them when they cry over their paper cuts or school yard scraped knees.
That is how I interpret God’s verses on children. God is infinite but respects weak and helpless people, both children and adults, so we should also respect the weak and helpless, in order to become partakers of God’s love and divine nature.