Human hubris
"(Moses) called the place Massah and Maribah, because the Israelites quarreled and tested the LORD, saying, 'Is the LORD among us or not?'"
(Exodus 17:7)
Let's face it... the Hebrew people that God freed from slavery in Egypt were a bunch of petty incessant whiners. Whether it was coming to the Red Sea, a lack of drinkable water, no (immediate) food to eat, etc... they complained early and often against Moses (and God). Moses had had enough (probably God had, too!).
In Exodus 17, the people are thirsty again. Evidently they haven't learned from the other MULTIPLE OCCASIONS when God came through for them. They've (repeatedly) forgotten that God can be trusted and counted on. So at their latest need (water again), they once more accuse Moses of bad intentions. Mo knows their quarreling and testing isn't just against him, but deep down it's against God.
The kicker (at least for me) comes in v.7. They asked, 'Is the LORD among us or not?' Now, on the surface, this looks like a legit question. HOWEVER... had they been paying attention to what had been happening in their lives, they would have known the answer: YES! OF COURSE GOD IS WITH THEM!
We human beings are so arrogant sometimes. We have a bad day... or go through a little adversity... (or, in our current COVID-19 situation, quite a bit of adversity!)... and we question God's existence (or at least God's interest in our lives). Wow. As if God exists to make our lives easy and care-free. How self-centered of us.
Maybe we should stop focusing on us and our perceived needs (which are often, if we're being honest, mostly "wants")... and start focusing on the needs of others. Who knows, we might get a fresh perspective on things (and do a little less petty incessant whining along the way).