Why does God care about us?

If God created the infinite expanse of the entire universe, then how, and why, would he possibly care about each of us on an individual level. This is a very obvious, and frequent, concern for anyone taking a journey through faith. And it's by no means a new concern. Indeed, David, himself, struggled with this (Psalm 8:4, KJV),

What is man, that thou art mindful of him? and the son of man, that thou visitest him?

Again, David says (Psalm 62:9, KJV),

Surely men of low degree are vanity, and men of high degree are a lie: To be laid in the balance, they are altogether lighter than vanity.

So why does God care about us on an individual level? Truth is, the bible never provides a complete answer, but from the front cover to the back cover, God is constantly trying to communicate that he does care. Genesis 2:7 (KJV), describes God's physical and intimate involvement in our existence,

The Lord God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul.

And that theme continues throughout the bible.  In Jeremiah 23:23 (KJV), God says,

I am God at hand ... and not a God afar off.

So let's not get lost in philosophical arguments about whether God pays attention to us. The bible emphasizes repeatedly that he does. Let's accept that closeness, and take comfort in it. As God says in Isaiah 43:2 (KJV),

When thou passest through the waters, I will be with thee; and through the rivers, they shall not overflow thee: when thou walkest through the fire, thou shalt not be burned; neither shall the flame kindle upon thee.