The faith part comes from interpreting the economic results of capitalism. Do you accept it as a useful economic system given all the problems you see with it? Are you willing to entertain the possibility of alternatives? If not, why?
Many also cling to the false dichotomy between capitalism and "soviet russia / north korea / venezuela"
Capitalism is the only hope of fending off environmental disaster, because it is the only system capable of producing the surplus needed to deal with it. When people are starving, they lose all interest in anything but their next meal, regardless of how they get it.
For example, the US was the first to clean up its waterways, and this is because the surplus generated by capitalism made it fairly easy.
Among the most capitalistic and consumerist societies (e.g. US) the pollution is staggering.
Interpreting results comes from evidence, not faith. One constructs a theory based on evidence. One tests the theory by seeing if future evidence behaves like the theory suggests.
Religion isn't like that, it does not predict things in a way that is testable. Creationism, for example, makes zero predictions and so is not at all testable, making it a faith, not science.
> Do you accept it as a useful economic system given all the problems you see with it?
Yes. Without question. Look around you - all the goodies you have were created by capitalism.
> Are you willing to entertain the possibility of alternatives? If not, why?
All the alternatives proposed have a historical record of being worse, often far worse.