Faith is like an invisible foundation.
It is where things come from and revert back to 

Keep-in The Faith

What is the importance of keeping the faith for hope and aspiration to be manifested in the process of getting there?

With faith you are like the little engine that could in you are saying "I think I can", to "I knew I could". 
Without faith we can dwell in the self defeating reasoning of  "I don't think I can" to "I knew I couldn't"

Some things are just that simple