Final answer:
In Hosea 4:13, the scripture indicates that 'My people' were involved in idol worship and pagan practices on the mountaintops, which signifies their departure from monotheistic worship and disobedience to their faith in God.
Step-by-step explanation:
According to Hosea 4:13, My people engage in idolatrous practices on the mountaintops. The verse describes how the people have turned away from their faith and are engaging in activities like sacrificing under trees and on the hills, which are often associated with pagan worship. This behavior is illustrative of the Israelites' disobedience and unfaithfulness to God, which is a recurring theme in the prophetic books of the Old Testament. Icons such as Hosea sought to call the people back to faithfulness and obedience to God's law, highlighting the consequences of their actions as seen in passages like Ezekiel 6:12-13, where judgment and wrath are described.
The mountaintops, in historical and biblical contexts, usually represent places of worship and are significant spiritual sites. They can symbolize closeness to the divine due to their physical height, reaching towards the heavens. However, in the context of Hosea, they represent a departure from monotheistic worship towards idolatry, which was strictly forbidden in the Israelite religious tradition. Examples of this behavior are vividly depicted throughout the biblical narrative, such as in the construction of the golden calf while Moses was atop Mount Sinai, as mentioned in the story from the book of Exodus.