If all religious doctrines are different as you say, and contradict each other (which is true by the way) and all inherently claim to be the "true path" (which is in fact what any doctrine of faith is: a statement of truth.), then there is a dilemma...
All religions are taught as "the truth"...even one that claims there are many paths to heaven contradicts those that say there is only one path...
That none are right is certainly a possible conclusion, however, if you accept this, you must accept that another conclusion is just as possible: that if one "is" right, then all others "must" therefore be false because of the contradictions in their fundamental tenets of faith.
Being born in Pakistan does not mean you must be Muslim, just as being born in India does not mean you will die a Hindu. And being born in the USA does not mean you will be a Christian. This premise is false. There are those who practice many different religions within most countries, even where the indigenous culture and religion does not permit such diversity or freedom of religion.
International travel and mixing of cultures is depending on the way you perceive it, to blame or the blessing for this diversity.
Religion is a choice. Faith is a choice. No one can force you to believe, and even if people are stolen and enslaved to become followers of a specific doctrine, those people can reject it, and have the ability to think and discern, and to willingly rebel against the teaching, even if it is within their own minds according to their own conscience.
Religion can be cultural, and it can be used to indoctrinate, but faith comes from understanding, and when people get to the age of understanding, they will have a choice to seek God in truth. If they doubt, and if they do not agree with a religious doctrine they can always question it or reject it...in many non Western countries there are penalty of imprisonment, physical pain or death for doing so, but they have the choice to reject what they know in their hearts to be wrong.
Culture to an extent is certainly a factor, but it is not the determining factor of how a person lives their lives.
God Bless!
Addition: This for anyone who says their religion doesn't say it is "the only way"....This statement alone is a statement of truth, that your religion implies, or leaves the door open that there may be another way.
If another religion says it is the "only way," and yours implies that it is not the "only" way, then inherently, those two religions contradict each other and cannot both be true.
If one is right, then the other is wrong.