Why is Christianity a universal religion

Christianity, is The fundamental idea of Christian universalism is universal reconciliation - that all humans will eventually be saved. They will eventually enter God's kingdom in Heaven, through the grace and works of the lord Jesus Christ.

As to Christianity being an universal religion. So says the Christians, having the backing of most of the powerful and influential countries. Ask a Muslim or Hindu and they will say that theirs is the universal religion, as it's the most suited for mankind.