Shared ground
Hosea 8:11–12 links two realities: Ephraim built many altars, and those altars did not produce faithfulness but more wrongdoing. The text does not treat “more worship sites” as spiritual health; it treats them as a multiplier of sin.
The passage also claims Ephraim was not operating with no guidance. The speaker says abundant instruction (“ten thousand things of my law”) was written for Ephraim, yet Ephraim regarded that instruction as “strange”—as if it belonged to someone else. Explicitly, the problem is not lack of teaching but rejection and distance from it.
Where interpretation differs (only where needed)
One difference is what kind of failure the “altars” represent. Some read the many altars mainly as unlawful worship sites (including rival or mixed worship), so the sin is the setting itself. Others think the point is broader: even if some sacrifices looked formally religious, the whole system had become a way to keep sin going, so the sin is the use and meaning of the worship, not merely the number of sites.
A second difference is how to take “I wrote.” Some understand it as a strong claim that God had given written instruction (through Moses and Israel’s Scriptures), now ignored. Others take it more generally as God’s communicated teaching—still authoritative, whether written down directly by God or delivered through his prophets and covenant tradition.
Why the disagreement exists
The verses are compact and vivid. “Altars for sinning” can point either to improper objects of worship or to worship practices corrupted in purpose. And “ten thousand” plus “I wrote” can be heard either as literal written Torah emphasis or as a rhetorical way of saying God gave extensive guidance.
What this passage clearly contributes
The passage contributes a blunt critique of religion that expands outward while separating itself from God’s instruction. It presents a diagnosis: multiplying religious activity can coexist with, and even reinforce, wrongdoing when God’s teaching is treated as alien. That is an explicit textual claim about Ephraim’s pattern, and a theological inference follows naturally: covenant loyalty is measured by response to God’s instruction, not by the amount of religious infrastructure.