Religions are belief systems that either reproduce themselves or die out. Like genes there will be a process that ensures or fails to ensure survival.

1. Judaism reproduces itself primarily by attachment to the Jewish race, hence the confusion as to whether the term might refer to a religion or a race. This confusion does not apply to the other two.

2. Christianity primarily reproduces and multiplies itself by conversion (preaching) and also by passing down the generations.

3. Islam reproduces itself by forcible conquest and then passing down the generations.