to suppose or think: to hold a view as probably true, often an assumption drawn from appearances that can turn out to be wrong
The verb νομίζω names the ordinary mental act of supposing something to be so. It is a tentative word: the speaker holds a view as likely true, not with the settled certainty of knowing. In the New Testament it very often introduces an assumption drawn from appearances that the story then overturns:
- the workers who "supposed" they would be paid more than they were (Matthew 20:10)
- the crowd that "supposed" Paul was dead after stoning him (Acts 14:19)
- the jailer who "supposed" his prisoners had escaped (Acts 16:27)
Because it is so often the verb of a belief about to be corrected, Jesus uses it twice to head off a misunderstanding: "Do not suppose that I have come to abolish the Law" (Matthew 5:17; 10:34). Yet the word does not itself mean "to be mistaken." It can just as easily carry a settled, reasoned judgment, as when Paul writes, "I consider this to be good" (1 Corinthians 7:26).
The verb grew out of the noun for established custom or law (νόμος), and in older Greek it could mean "to hold as customary" or "to acknowledge a god." That older sense has faded by the time of the New Testament, where the word settles into the plain meaning "to think, suppose, consider." Its near neighbors are δοκέω, οἴομαι, and λογίζομαι, each shading the act of forming a belief a little differently.