To a degree that might be true of Hinduism, being naturally polytheistic. Not so true of many other religions though, where whatever interfaith progress has been made has been largely due to people's basic humanity shining through despite their religion, not because of it.
Two billion people identify as Christians. This is across continents, race, language, economic status, gender, age and all other differences. Similarly Islam has 1.5 billion. Hindus 1 billion and Buddhists 400 million. No nationality or other political or economic grouping can claim a similar kinship or integration.
Maybe there are minor differences within these groups but that is what humans are like. Even a small country like UK has its divisions and differences within themselves. Even a tiny island like Ireland has its division.
Just imagine millennia ago how many different tribal groups with geographic, racial, linguistic and economic differences would have existed in Asia, Africa, Europe etc. It is religion that has brought most of them together under just a few groupings.
Such a phenomenon is unthinkable without religion.
Also, most of the values of humanism, compassion, universal brotherhood, equality, sharing that we today believe in has been possible only because of religious teachings over the centuries.
This is besides the hundreds of charitable institutions, hospitals, education institutions and so on, that have been run by religious groups.
Religion has been the single most civilizing and integrating force on this planet all these centuries. There is no doubt about that at all.
