Over the years (but especially recently,) religion has gotten a bad reputation for driving people apart. While this may be true for first dates and family reunions, it is not the case when we look at the broader picture. After all, religion brings together people of all ages, races, genders, cultures, and backgrounds, and unites them with a shared belief system. A young Hindu woman from America will share the same beliefs about morality, love, and the creation of the universe as an old Hindu man from India. Bonds like these are powerful, and are typically found only in a religious context. Apart from benefiting individuals with a sense of belonging, the communities forged together by religion can benefit society as a whole. For example, there are countless religious outreach organizations designed to help the poor and needy, from the Salvation Army to Samaritan's Purse to Compassion International. On a more nuanced level, strong communities of believers can lead to strong communities as a whole. After all, regardless of whether or not everyone agrees on the specifics of a given faith, the majority of religionists have the same goal: to help those in need and make the world a better place.
This argument massively downplays the amount of division that differing religious beliefs have caused throughout history. Not only does religion cause conflict among individuals, but it can create great friction on a societal level, sparking atrocities like the Crusades, the Salem Witchcraft Trials, and 9/11. While any given religion certainly unites believers, it sets them apart from the rest of the world, making "in-groups" of saints and "out-groups" of sinners.