Probably the only reason that you and I, & 98% of Christians ARE christians, is because of the culture we are bought up in, which was a Christian culture. There is probably only about 2% of Christians who were bought up in a different faith or culture who actually convert to Christianity.
So if I was bought up in a Muslim culture, I would still require faith to believe, but my belief would almost certainly be faith in Islam. The same goes for all the other religions.
So what is the use of having to believe in something supposedly as important as believing in the right God or religion, or you might end up in hell, on faith?
If I get on an aeroplane to fly to another country, I can have reasonable faith that I will arrive at my destination unharmed. If I didn't have that faith, I wouldn't get on the plane. So yes, a certain amount of faith is useful. HOWEVER, my faith is not blind faith, my faith is based on the following facts:
1. The Science behind aeroplanes being able to fly is very well known & well-proven.
2. The particular plane I am boarding has done many successful flights before
3. I am assuming the plane is well maintained according to Civil Aviation regulations
3. I know that the pilots are well trained
4. I know that air flight is one of the safest forms of travel, safer than most other forms of transport.
So my faith is based not just on somebody telling me that it is safe to fly on the plane, my faith is based upon solid EVIDENCE!
So for a god to expect people to believe in him based on FAITH alone, is quite cruel. Because god also knows that:
1. If people are expected to believe on faith alone with no solid evidence provided, many (well over 2/3rds the world's population) will choose the wrong religion to believe in, based upon their culture, or the religion that their parents believe in.
2. There is always going to be a percentage of the population that cannot believe through faith alone. A certain percentage of the population is always going to require solid evidence before they believe certain things.
3. Without compelling evidence to support it, there is no reason for believers in one religion to change to another religion, because they may be leaving the true religion for a false religion.
So the only conclusion that one can come to, is that heaven is a fairly small place. So god needs to keep the numbers low, so it won't be too crowded there, & he has deliberately rigged the system so that less than a 1/4 of the world's population ends up in heaven.