As you can see, the gap between Islam and Christianity are decreasing. I fear that in a few decades it will overtake it as well as the impending spread of atheistic thought. Christianity is practically dead in some countries in Europe and the long and hard centuries of getting Christianity to the point where it is today is starting to disappear as churches do nothing. I think it is up to strong Christians to stand up against the evils and threats that impose on Christianity and spread the Gospel of Jesus Christ.
Do you think Christianity is failing and will be overtaken by Islam?
Globally Christianity is one of the fastest growing religions, particularly in the far East its proving popular in China and South Korea is now officially a Christian rather than a Buddhist nation. Islam is growing but much of that is due to population increase they're not really winning new converts. In much of Europe organised religion is more or less dead though I'm not sure if that has anything to do with a rise in atheism specifically.