Their God is a modern abstract one, they embrace science fully and accept god as the cause of reality as we discover it through science. Meaning that there's not really much for their god to do on a day-by-day basis. Like many modern god believers, there god is pretty much reduced to a simple "First Cause" god, with no real need for it do actually do anything beyond an initial creation.
However, Bahai is strongly interfaith and does believe nontheless that their God has sent a series of prophets and messengers, such as Muhammed, Jesus, etc, and as many other respectable spiritual leaders as the founders could think of. In their theology, it is said that such leaders come once every few hundred years. Despite this, Bahai' claims the inspiration of a rapid succession of two prophets, the Bab, and then Baha'u'llah. In keeping with Arab culture, any worship of the messengers themselves is detested and considered heresy.
"Salvation lies in the search for truth as revealed by the Manifestations of God -- the achievement of spiritual perfection and closeness to God, deliverance from one's imperfection or base nature This is achieved by faith in God and strict obedience to the commands of God; turning to the latest Manifestation of God, Bahá'u'lláh, for spiritual guidance; study of the scriptures of the Manifestations" from this summary (from a quiz) you can see why it's a big inter-faith religion. The UN has a disproportionate number of Bahai's in prominent places, and I think the religion may well climb right up there besides international Buddhism for peacekeeping issues. (For example, serving others is the closest thing they've got to a sacrement and is considered a form of worship).
Bahai' does have some of the traditional values associated with monotheistic religions, such as anti-homosexuality. But aside from those, Bahai' is one of the best monotheistic religion (of a rotten bunch), and I'd like to see it become a real world religion, although their theology is just as messed up, I don't care about that, it's not as anti-intellectual as most monotheistic-isms.
You see, it has the ability to liberalize arab culture in a way that Sufi or other slightly-alternative Islamic faiths have failed to do. And anything that can begin to bring Islam out of the dark ages is a good thing. (Even if it's not as good as, say, being moral without religion at all).
So... go Bahai go!
Along with Pantheism and Liberal Christianity (or what's left of liberal Christianity anyway), Bahai is a nicely progressive religion with a suitably vague god (read: small and unobtrusive) to suit the scientific future.
http://www.vexen.co.uk/books/momen_tpor.html is an excellent book on religion in general "The Phenomenon of Religion", the author is a Bahai', it's a voluminous book covering many aspects of religion including history, beliefs, psychology and sociology in a balanced and scholarly way.