Origin of the A-OK hand gesture

Factual Questions
1

When I was young and forced to attend church (including the pre-church service Bible school) there was some talk about the origin of the A-OK hand gesture. The story was that the early christians used a hand sign to signal to each other their common belief when they were persecuted in the early days of the religion. The hand gesture they used was very similar to the current day A-OK hand sign.

Today, we make the sign by forming a circle with the index finger and thumb and holding the other three fingers straight in the air. Rumor has it the early christians formed a crude fish sign with the index finger and thumb - instead of a circle the thumb and index finger are crossed - and it looks something like a ichthys.

The wiki doesn’t give an origin for the gesture but does say that there are both positive and negative meanings. In one culture it means ‘ok’ in another it means ‘you are a zero’.

Is there any truth to the story I was told as a child? What are the chances early christians flashed signs at each other like members of a gang?

2

Not at all likely. Given that the sign has negative connotations in many parts of the world, including some Arab countries and Turkey, where all those early churches were, and given that many modern Christians believe it stands for 666, I don’t think there’s any coherent case to be made for any meaning other than the obvious ones.

Most likely, it means “OK” to us because it looks vaguely like an O and a K.