Anxiety was endemic to the ancient world because the agricultural tech was able to support large populations but the life of each individual member of the population was vulnerable to disease an inter and intra-specific predation as well as resource failure e.g. famine.
Terach developed the treatment protocol of idolatry. Patients were instructed to create a physical representation of a figure that could reduce anxiety — usually an idealized parent — mother or father (Marduk or Ishtar) but sometimes an idealized king. In the event of anxiety patients would talk to the idol and ask for protection. There were also portable idols to be carried in the pocket or worn as jewelry.
The son of Terach, Abraham, encountered the syndrom of Idol Anxiety. Patients would worry their idol would fail, was in disrepair, had been constructed poorly, was angry at them, and feel anxiety. Abraham developed Monolatry — the construction of a mental or imagined idol, which would not suffer the vulnerabilities of a stone or wooden idol. Patients were instructed to imagine the idol either in the sky or in their heart, because the sky would remain present always, and the heart would remain present for the duration of the patient’s life.
Legend has it that Abraham destroyed his father’s therapeutic practice, actually destroying his idols. More likely this was an economic attack — his competing practice drew clients away from his father’s.
A more charitable reading of the legend is that towards the end of his career Abraham imagined his idol as like his father — a paternal presence that followed him constructing idols to soothe his pain as the situation demanded. Every person, every day, every breeze and ray of sunshine was an idol his father constructed for him.
On this reading Terach’s ultimate idol was his own son, who relieved his anxiety with the hope that his compromises with anxiety would some day no longer be needed.
From what I know of fathers and son I am sure Terach thought that, but also sure that he had a voice within him that said “Some day. But not yet.”