Christianity has a Savior that all can focus upon. He is a guide in their lives, a man of peace and love and charity to all. He loved all mankind so much that He gave His life for them that if all repented they could dwell in a much better place than what man has created for himself. Christianity is not a difficult religion to live, it is kind and gentle and holds no animosity towards any other religions.
So they can appeal to Christians (and other people) and get more followers.
A universalizing religion seeks to appeal to all people worldwide, regardless of their background. It often aims to spread its beliefs and practices to all societies in order to achieve global adherence. Examples include Christianity, Islam, and Buddhism.
Christianity appealed to people because it has the answers to the important questions in life. eg Why are we here? What happens to us after death?
About 2.2 billion people, nearly 33 percent of the world's population
Stolkholm Conference (1972) which produced the Declaration on the Human Environment. The conference made an appeal for the introduction of Environmental Education worldwide.
Christianity is worldwide, but appears to be strongest in English-speaking countries.
Christianity I hope.
Worldwide, that would be Christianity.
6.2 billion
There are an estimated 2.1 billion followers of Christianity.
Amnesty International is a worldwide, movement of people campaigning to protect human rights. It has no religious affiliation, but respects the religions of all people.
Now, worldwide with over 2 billions people who call themselves Christian. The 'most' Christian nation is the U.S.A..