That they may not become too complacent or delighted in married life, he makes them distressed by the shortcomings of their partners, or humbles them through willful offspring, or afflicts them with the want or loss of children. But, if in all these matters he is more merciful to them, he shows them by diseases and dangers how unstable and passing all mortal blessings are, that they may not be puffed up with vain glory.