Here’s part 2 of your big question. I hope you were able to read and understand part 1. If not get back to me and I can clarify.
People’s beliefs are very strongly influenced by their culture and family. But this does not mean that they are not responsible for them.
Our culture and upbringing give us a context in which to view and interact with the world. While we are young we may not have much say in it and tend to take on board the belief of our family and culture without much questioning. But growing up is about questioning all these things and working out for ourselves what parts of our upbringing we want to accept and what we want to reject. This is why society and culture change over time. (I’m not a sociologist but say this as a keen observer of life).
So culture does play a big part in forming our belief system and does form a (sometimes) formidable barrier to change. But we can choose to think differently. There are plenty of examples of people who were raised as muslims becoming christian and vice versa. So you cannot conclude that since someone was raised (say) a muslim, that they should not be held to account for that belief. People who strongly believe something tend to do so because they have chosen to (unless they have been brainwashed - which is something I don’t want to address here) .
I think one of the most important things about a belief system is that it should be open to questioning. After all, my belief system is what helps me to interpret what goes on in the world. When it stops being able to do that, then I should be able to question it and change it - this is what learning from our expereinces is about.
This is the way I treat my Christian beliefs and I believe the bible teaches us to do this.
Christianity is based on a series of historical events that have been witnessed and written down. It is a belief system that is based on evidence that can be read, studied and discussed in a rational manner. It is to be constantly tested and reviewed in the light of life’s experinces. Because if it is the truth then it will always stand up to scrutiny.
I was brought up in a non-christian family and never went to church. When I was 13, someone told me about Jesus and I accepted that what was said to me was true and I put my faith (trust) in him. The last 40 years of my life has been a process where my understanding has grown and my trust deepened as I read the bible and tried to make sense of the world. I am still a Christian because the evidence of the bible backed up with the experiences of my life makes the most sense of the world.
But I would give up Christianity if compelling evidence were presented to me that Jesus did not exist or he did not rise from the dead because that is the heart of the Christian faith. It would be unethical of me to seek to convince someone else to change their beliefs if I were not prepared to change mine.
John, it appears to me that your questions come from the fact that your existing belief system does not seem to answer all your questions. Have a look at the bible. Forget what you were told as a child, look at the evidence yourself and ask whether it makes sense of the world.