Final answer:
Christianity is the religion with the most followers globally, numbering over 2 billion. It is followed by Islam, Hinduism, and Buddhism in terms of the number of adherents. Secularization affects some areas, yet Christianity remains predominant, while Islam is growing rapidly.
Step-by-step explanation:
The religion with the most followers globally is Christianity, which has over 2 billion adherents. This monotheistic religion, which focuses on the teachings of Jesus Christ, is the largest in the world and has a significant presence in various countries, including India where it is the third-largest religion. Despite trends towards secularization, Christianity remains the most practiced faith ahead of Islam, Hinduism, and Buddhism. Islam is currently the second largest, with about 1.5 billion followers, and is the fastest-growing religion, expected to increase in adherence. Meanwhile, Hinduism ranks third with approximately 900 million followers, and Buddhism comes fourth; however, the actual number of Buddhist adherents is likely higher than often reported due to underrepresentation in regions like China.