"Do not be idolaters as some of them were; as it is written, “The people sat down to eat and drink and rose up to play.”" (1 Corinthians 10:7, ESV)This verse refers back to Exodus 32:6. The context of this reference that the Lord has just finished giving Moses the tablets of the testimony on Mt. Sinai in chapter 31, and the Israelites, losing patience with Moses and with the Lord, have asked Aaron to make them new gods. Exodus 31:1-6 is worth quoting at length:
When the people saw that Moses delayed to come down from the mountain, the people gathered themselves together to Aaron and said to him, “Up, make us gods who shall go before us. As for this Moses, the man who brought us up out of the land of Egypt, we do not know what has become of him.” So Aaron said to them, “Take off the rings of gold that are in the ears of your wives, your sons, and your daughters, and bring them to me.” So all the people took off the rings of gold that were in their ears and brought them to Aaron. And he received the gold from their hand and fashioned it with a graving tool and made a golden calf. And they said, “These are your gods, O Israel, who brought you up out of the land of Egypt!” When Aaron saw this, he built an altar before it. And Aaron made a proclamation and said, “Tomorrow shall be a feast to the LORD.” And they rose up early the next day and offered burnt offerings and brought peace offerings. And the people sat down to eat and drink and rose up to play.The people were growing impatient with Moses and with God: "When the people saw that Moses delayed to come down from the mountain..." As throughout the whole section of chapters 13-19 that Paul was referring to before, they still don't seem to trust the Lord even after all He has done for them. So they decide to make some new gods that they can follow and trust (the prophets delighted in pointing out the absurdity of trusting in gods you made yourself). I noticed for the first time the incongruity: Aaron makes a single golden calf and then the people say, "These are your gods, O Israel, who brought you up out of the land of Egypt!" As if they simply weren't comfortable banking entirely on a single god. And then it gets stranger: after making these idols, Aaron says that "Tomorrow shall be a feast to the Lord", and they bring offerings (to the true God or the golden calf, it's not clear). Finally, in the verse Paul refers to, the people just party and do whatever they want.
There is more going on here than merely exchanging worship of the true God for a false one. The Israelites still seem to keep honoring God, at least in lip service. In the polytheistic, paganistic culture from which Judaism arose, the existence of multiple gods was not controversial. Families or tribes would have a favorite god that they paid the most respects to, but they would also recognize and honor other gods, because hey, a little more blessing couldn't hurt. This kind of polytheistic worship—not rejecting the true God outright but demoting Him to merely your favorite god to worship or even a peripheral god that you superficially honored to avoid getting whacked—was a huge problem for Israel through the time of the kings. The most controversial thing about Judaism was that its God demanded exclusive worship and devotion—not to simply be added to your own personal pantheon of deities.
Thinking about it, I see Moses and the Israelites displaying two totally different attitudes both under the guide of "worship". Moses was a servant of God. He did what God told him to do, went where God told him to go—basically laid his entire life in God's hand, like so many other imperfect heroes of the Bible (and Jesus). The Israelites, on the other hand, seem more interested in how God will serve them. They expect to be practically pampered through the exodus, complaining against Him when things aren't up to their expectations, and then God seems to be taking too long, not holding up His end of the deal, they turn to another god who can better cater to their whims (while still hedging their bets with God).
This sounds uncomfortably like me. This kind of exploitative attitude, serving God as a way to get things from Him, used to characterize my faith. And it is a pervasive temptation. When we are merely giving God things like our time, our money, our service, our blog posts, and merely getting from Him things like a better life, a new community, a set of rules to live and judge others by, or even salvation (as a "get-out-of-hell-free card"), our relationship with God looks more like a business partnership. He has His interests, we have ours, and by working together we can satisfy those interests while still remaining essentially our own. But the truth of the gospel is that "You are not your own, for you were bought with a price." (1 Corinthians 6:19-20, ESV). We don't merely give God things and receive things from Him; in love we give Him our selves and receive the greatest prize of all, God Himself.