There are those on this site who pm each new ex JW God-believer to get them onto the Jesus-as-saviour delusion as an alternative to the Watchtower delusion.
Religious and spiritual "belief" have a very long pedigree as the earliest examples of writing bear evidence. (Have you read Gilgamesh?). Not only have reverence for God or gods been instilled into the young of every preceding generation back to the Stone Age but vast and revered organisational colossi such as the RC Church exist, bearing testimony to the need and success of sustaining existential comfort by idealized yet foundationless belief in a spirit world.
The RC Church had long ago reached the point where its dogma is believed not because it was true or even found in the Bible but because of its own magisterial authority, cemented by time, tradition and the vast number of followers. Can billions of followers be wrong? Can millions? It is the very route the WT society would love to take but need a lot more money to achieve! Plus the fact that doomsday cults are limited by their necessarily impermanent nature.Yet religious belief still works as a makeshift patch to cover deep psychological problems and insecurities and ironically for JWs, many of them of the WT's own making.
However Etude, you speak of the ultimate conversion. My response is to suggest that it happens when we grow up (at any age) and start to use reason and testable evidence as the basis on which we make our important decisions.