Why some people stay in manmade religions
 
A religion made up by man is bad by default for what right has man to control your religious beliefs and religious morals?  Why is any doctrine you make up not as good as what the Church makes up?  If a religion is man-made then it will be in error for it thinks it is divinely inspired. A true system can become corrupt but a false one or misguided one is far more likely to become corrupt. You have to leave for you cannot be so arrogant as to assume that you can remain immune.  If enough arrogant people think the way you do then the religion will get drunk on arrogance and you know what will happen!  Violence.

Some people stay in a religion they know is man-made and wrong.
 
Staying in a religion you know is not really the one true one means -

You don’t care about truth - for you one religion is as okay as another
 
You get pleasure and praise by affiliating with the religion
 
You like being part of man's scheme to have his doctrines and rules glorified as those of God
 
You are dishonest. And if you really think one religion is as good as another why are you so keen on staying in the one you are in? You think this is about you. It is not just about you.
 
You are too afraid to leave for the community will not approve
 
You are encouraging them to bully people to stay
 
You put externals - eg the appearance of being a believer - first.
 
You are only externally a member of the religion but not internally and internal is more important.
 
You feel the religion might still be true and you could be wrong.
 
It is the religious conditioning that makes you feel that way and is affecting your confidence that you can find out if a religion is false. The solution is to see that if you can see that other religions are false you can see that your own which says they are false is false itself.
 
Religion cannot convince by evidence and reason alone so it needs miracles. The miracle is supposedly a communication from God that something is true even if it does not seem believable. This kind of thinking is parasitic on the fact that not all true things are believable. Miracles probably make the ex-believer too scared to make an official break from the religion.
 
The solution is to see that rather than trying wonders and visions and sudden healings to get converts, a decent God would work inside the person to heal vice. It is the kind of person you are that matters - not what miracle accounts you believe in. Those who preach miracles should keep their tales to themselves for they undermine this beautiful principle.
 
You feel that if you depart the religion you are setting an example for others and their morals might fall apart without faith in the religion. That is a sign that you suffer from the prejudice that other religions or becoming irreligious lessen how good people can be or ruin it altogether.

Hypocrites and those who call themselves good Christians or whatever and reject Jesus’ teaching because it does not suit them are drawn to their religion and keeping up the religious appearances because of the values and ideals. People are drawn to those values and ideals but being attracted by them means nothing if you are not going to live them.
 
The religious label when socially accepted becomes in a sense political.  Take Catholicism.  If Catholicism is a man-made religion, calling somebody Catholic is really just a word. It has as much validity as saying a man from Rainville is a Rainvillian. There would be nothing special about the label except as a social appellation. And that is nothing.  But it is treated as more than that and that is bad.  Labels have led to more death and destruction and bigotry than we can ever imagine.  Don't be a part of the problem.  Ditch the label.

Not a single reason for staying is a good one and only makes things worse in the long run. If you can’t leave on your own, fine but encourage others to leave and you can all leave together.