eidos denotes a visible form or appearance, and also occurs in phrases contrasting faith with appearance or qualifying evil.

The dominant attested use concerns visible form or appearance: the Spirit descends in bodily form, a face's appearance becomes other, and a form is not seen. In two genitive phrases, the term is associated with walking by faith rather than appearance and with abstaining from every form of evil.

1. Visible form or observable appearance · dominant

   In Luke 3:22, the dative singular form occurs in the clause where the holy Spirit descends in bodily form like a dove. In Luke 9:29, the nominative singular form is linked with the appearance of a face becoming other; in John 5:37, the accusative singular form is the form said not to have been seen.

   Luke 3:22Luke 9:29John 5:37
2. Appearance or form in qualifying phrases · occasional

   The genitive singular form occurs in 2 Corinthians 5:7 in the contrast between walking by faith and not by appearance. In 1 Thessalonians 5:22, it occurs in the instruction to abstain from every form of evil.

   2 Corinthians 5:71 Thessalonians 5:22

In the Anselm Project Bible: The APB uses “bodily form,” “appearance,” and “form” in these verses. These renderings confirm the clauses' presentation without fixing a separate English equivalent in every occurrence.