You asked about the problem of which denomination to join. The important thing is to get the spiritual food you need, and you have every right to get what you want from wherever, regardless of what the denominational franchise may think. Here is a children's story to illustrate what happens. I will use the names of grocery franchises here in Canada, and you can guess which deonomination they illustrate.
Once upon a time people bought food from their local grocery stores. Then one of these stores named A & P got so strong that it began to set up a chain of stores in more and more cities. This proved to be so profitable that Dominion also began a chain in the western part of the territory. In some places they overlapped, and quarreled. Dominion began claiming that they were the only store appointed by God to sell food for all people. They made rules that anyone who did not submit to them would not be allowed to buy food anywhere.
Eventually other chains opened up under such names as Food City and No Frills. The resulting confusion brought the government in to regulate who could sell food in every town of the realm. Some governments fought wars about this for a hundred years. People were so disgusted that they went back to patronising their own local grocery. But these local stores found it hard to manage on their own. Soon the idea of franchising emerged. Each store was independent, but they were supported and to some extent controlled by the new Independent Grocery Association franchise. Naturally IGA and other Independent franchises were hated by Dominion.
But the franchise idea caught on and eventually all the big chains worked the idea. It allowed local initiative, and by collecting twenty per cent of the take the franchise honchos were able to build bigger offices, pay themselves suitably, and organise themselves to fight the other franchises.
At first they managed to persuade people that no one was allowed to buy grocery at more than one store. But the food buyers told them to get lost. They would buy their food wherever there were specials without a shred of loyalty to any franchise. And many people grew their own food and used mail order and internet facilites to get what they wanted at half the price.
Meanwhile the franchise honchos all dreamed of running one big franchise for everyone. Nobody, but nobody, would be able to buy food except through the one organization. This would be cost effective and provide one franchise office for the whole world. The honchos began spending millions of hours flying all over the world and meeting in committees to achieve this desirable unity. They also managed to persuade good gullible people that the one problem about food was the problem of disunity. And that problem was caused by all the other franchises being selfish and power grabbing.
But the problem for ordinary people was being able to find pure nourishing food for their kids at a price they could afford. So new grocery stores kept opening, grew bigger, and got the idea of organizing franchises in other countries.
An interesting development has just occured in what had been A & P territory. That franchise had become so greedy and oppressive that the people revolted and got the government to close them down for seventy years and sell all food without them. But the government was even worse, and when it was eventually toppled every IGA franchise from North America came in to occupy the territory. But the A & P honchos (you can tell them from their black gowns and hats) have just made a deal with the government to make all other franchises illegal in that area.
Children, the moral of this story is that people need food, and God provides all the rain and sunshine needed to grow it. But you will always find greedy people who try to corner the market.