Are not two sparrows sold for a penny? And not one of them will fall to the ground apart from your Father. But even the hairs of your head are all numbered. Fear not, therefore; you are of more value than many sparrows (Matt 10: 29-31).
—Huldrych Zwingli (Protestant Reformer), The Defense of the Reformed Faith, 145.
We cannot but admit that not even the least thing takes place unless it is ordered by God. For who has ever been so concerned and curious as to find out how much hair he has on his head? There is no one. God, however, knows the number.
Indeed, nothing is too small in us or in any other creature, not to be ordered by the all-knowing and all-powerful providence of God.
These words remind me that God's providence enables me to trust.
I think this also means that a sustained "fear" of what may happen to me or my family exposes a lack of trust in God's sovereign hand and essentially demonstrates disobedience to Christ's command to "fear not."
Jesus argues that the truth about the lesser matter demonstrates the truth about the greater matter. Insignificant little birds do not escape the guidance of their creator, so why would I fear his neglect?
The sparrow flies and falls within the scope of providence. If a bird cannot fly high enough or travel far enough to escape the grasp of God's guiding hand, then why would I entertain the notion for myself?
An implication of this truth is that I'm not to worry, fear, or be anxious about what happens to my family; about my dad who is battling leukemia; or my daughter who is forming in my wife's womb. Jesus exhorts me to take my fear of chance and circumstance and transfer it into trust in providence and his good pleasure. Hope. Trust. Prayer. These are the actions appropriate in a world that he is guiding. Trifling matters do not exist in this world; only intricate details.
God is sovereign over sparows. So too, white blood cells and amniotic fluid.
"I believe; help my unbelief"