Because people want to live
Because people want to live forever in a paradise be it in heaven or earth. It like a carrot you dangle before and animal to get him to move in a beneficial way for profits.
We will suspend critical judgement if we engage in wishful thinking and lots of times we were born into a religion and so not having the critical thinking skills we naturally fall into the delusions of christianity, It is like the old computer saying garbage in = garbage out in other words we have been feeding our minds with pretty much useless information and now we are getting garbage out.