You can have faith in a person, but what if that person turns out to be a liar or worse, a deceiver, who pretends to be one thing, but is actually a phony. Politicians often say that they are in favor of a specific thing; but when they get into office, they often do something that is virtually the opposite of what we expected. Clearly having "faith" in politicians is a shaky proposition at best.
I can believe with all my heart that I can fly. I can visualize myself flying, I can recite positive mantras like "I can if I think I can". I can think about flying day and night, and I can imagine myself, arms open wide, floating on the warm afternoon breeze. But the minute I spread my arms and jump off the cliff, my faith will be shattered, (along with a few bones), as I quickly realize that my faith had been placed in something that simply was not true. I can't spread my arms and fly, no matter how much faith I have in my physical flying ability.
On the other hand, If I am a pilot who knows how to fly a plane, I can fly and I can have faith in my ability to fly. As long as I am following the rules that govern flight - the absolute laws and truth of aerodynamics, then I can fly. But in this case, my faith is not in myself or my own ability to fly. My faith is placed in the truth of the laws of physics. Those are absolutely true and will always yield a predictable result, as long as I stay strictly in compliance with those laws. They are true, absolute, and they are immutable. Faith placed in something that is absolutely true yields power. Faith placed in something that is wishful thinking, rather than truth, has no power. This is why truth has real power.