If we could all understand and practice that each religion is a valid and valuable part of the whole, then I think it would be possible.

This is the real truth. No religion that I know of teaches the whole truth.

The differences of religions allow for the different personality types. What is bad or degrading for one is empowering and enlightening for another.

The merging will allow each his own so to speak. That way just because you live in India, you wouldn't have to be a Hindu. Men would not have to suffer the emasculation that the Catholic faith brings. It would be like college where you choose your major. There would be the basic core classes, then you take upper level classes in the religion that fits your personality type or your interests.

That is happening on a small scale now, because of the internet and widespread translation and circulation of literature.

The biggest factor is in the education levels around the world. In order to study esoteric or philosophical subjects, there has to be time, access to materials, and a mind that has absorbed the basics in reading, literature, math, and the arts.