How many Christians are there worldwide?

Answer 1

• Many sources mention 2.1 billion Christians in the world (about one third of the total population of the planet), but estimating numbers is fraught with difficulties. What is included among the definition of 'Christian' is not agreed upon by many of the groups involved.
• The term 'Christian' in its simplest definition refers to one who believes in Jesus Christ (as God). Drawing the line between 'Christian' and those who belong to 'sects' is problematic. Add to this the fact that no-one can really tell if a person is a Christian at heart, or if they are just paying lip-service to the name. This is impossible for any but God who sees the heart to judge. The numbers can be taken, then, as a best estimate of how many identify with Christianity in some way.
• However, it is now impossible to say with any certainty, as, while practising Christians have been in decline in some Western countries, there has been a recent surge in 'membership' in parts of the West, and in the East the numbers who are becoming new Christians daily is astronomical. There are estimated now nearly 100 million Christians in China (compared with just 5,000 in the 1960s) and in South Korea, churches regularly have tens of thousands of members each. In one church, the Yoido Full Gospel Church in Seoul, there are over 800,000 members who meet each Sunday in several sittings in a vast hall. So, whilst it is difficult to give a definite answer to the actual number of Christians in the world (estimates range from 2 - 3 billion), Christianity remains the most dominant of the world, and is still growing at an astonishing rate.

Answer 2

As of 2005 (most recent data), approximately 88 percent of the world's population were said to "believe in God" (Cambridge University). This is down from 96 percent in 2000. In the United States, 95 percent of the population "believe in God."