J witnesses go door to door to recruit more ppl. But at the same time they believe only 144,000 ppl go to heaven

So why do they try to make more of a competition , if they believe. That out of all the population ever to have lived only 144,000 will be saved ; and the rest will burn in hell This isn’t an old religion but a new one ,made in 1890s like um How does this make sense ?