Matrix Of The Atheist: A Rational Fideistic Defense of the Christian Faith

What exactly does the Christian mean when he/or she says they have "Faith in God"...? Is it a reference to having faith that He will do and accomplish all that He has promised to do? Such as regenerate us and seal us with the Holy Spirit, along with instilling within us a new nature with new desires? Does it mean we have faith He will give us the power to overcome sin and temptation? Perhaps it means we have faith He will provide for us eternal life and upon the end of our journey here, we will dwell with Him forever in Heaven? Or, whenever we assert we have faith in God, does it mean we have faith that... He exists?