Jesus described "faith" as a servant that is sent out, and then returns back after accomplishing its job.
Once "faith" returns, it is sent out again.
Faith does not grow in strength from small, medium, and then gumbo size. Faith does not grow in quality, but in quantity.
There is only one faith, but that one faith can do multiple things all at the same time.
A Christian can have faith, and unbelief at the same time also. You can have faith in your salvation, but have no faith in believing God will provide all your needs.
Luk 17:6 And the Lord said, If ye had faith as a grain of mustard seed, ye might say unto this sycamine tree, Be thou plucked up by the root, and be thou planted in the sea; and it should obey you.
Luk 17:7 But which of you, having a servant plowing or feeding cattle, will say unto him by and by, when he is come from the field, Go and sit down to meat?
Luk 17:8 And will not rather say unto him, Make ready wherewith I may sup, and gird thyself, and serve me, till I have eaten and drunken; and afterward thou shalt eat and drink?
Heb 11:6 And without faith it is impossible to please God, because anyone who comes to him must believe that he exists and that he rewards those who earnestly seek him.