You can drink water out of a cup, a hose, a river, a shatter-proof bottle, or run through a complex filtration and distribution system. But it’s still the water itself that hydrates you. It’s the only thing that does.
You can disseminate the Gospel through tracts, personal conversation, crusades, blogs, cell phones, laptops, or PDAs (as I type this on my BlackBerry). It’s still the Gospel, and only the Gospel, that is God’s power to salvation.