Faith deals with things mostly unseen. Once that seed of faith has been allowed to germinate, you have to continue to feed it. You have to read your Bible and you have to pray. Those two things feed your faith.
There will come a time in your life, like it is in mine right now, that all you will have to hold on to is the word, "faith", itself. It will seem that nothing and no one knows or can be bothered to care. It is at that time that you march resolutely on, saying like Job, "Though He slay me, yet will I trust Him."
I was going to go into a deep discussion on faith and make several key points and applications, but you have the gist of it.
Aside - The person that you see
Who seems to be strong
Is engaged in a battle and has
Been there overlong.