One would think that, if altars are increased during a period of prosperity, as verse 1 states, then religion must be flourishing. Indeed, religion was flourishing! Amos, Hosea's contemporary, clearly reports this in his book. However, what was flourishing was not the religion God gave through Moses but idolatry. Notice in verse 2 that God accuses Israel of having a heart that is divided.
Ironically, commentaries have divided opinions over what the Hebrew word translated "divided" means. Most modern translators render this word as either "false," "deceitful," or "faithless." None of these are wrong, including "divided," because the Hebrew word indicates "smoothness." It all depends on the context in which it is used. It can also suggest "flattering," which ought to give us a clue that it describes people who "talk the talk but do not walk the walk." Notice Isaiah 29:13:
Therefore the LORD said, "Inasmuch as these people draw near with their mouths and honor Me with their lips, but have removed their hearts far from Me, and their fear toward Me is taught by the commandment of men. . . .
Isaiah lived just before Amos and Hosea. However, he was a prophet to Judah primarily, whereas the other two men were prophets to Israel—the ten northern tribes. What Isaiah says agrees with what Hosea says. These people were flattering God with their tongues, but their hearts were not really in what they were doing. Reverence for God, then, was merely an intellectual accommodation intended to appease Him. They acted as if God could not see right through them! It shows how far off-base and carnal they were in their thinking.
They used the name of God frequently, undoubtedly claiming that they trusted Him, just as we do today. All of our coins and paper money read, "In God We Trust." Yet, these people filled the nation with lying, stealing, murder, adultery, fornication, coveting, Sabbath-breaking, and idolatry, all the while giving Him lip service with their mouths—talking the talk but not walking the walk. This is why God says, "Your heart is divided. It is deceitful. You talk so smoothly, but your heart is false."