Unborn children in the womb are so united to their mothers by the umbilical cord, that what affects the mother affects the baby. Though mother and child are separate individuals, you can accurately say that the baby is in the mother and the mother in the child. – And this is like a picture of the union that has taken place between God and the believer.
Source: Neil Anderson & Rich Miller, Getting Anger Under Control, 2002, Oregon USA: Harvest House, p.115