I see only three possible motives:
1. Purely a campaign photo op to perpetuate his “image.”
2. They have a larger crowd at church than at his campaign events.
3. He is praying for his own reelection....though I have doubts about his REAL knowledge of prayer.
Uh.... four.
Obama needs a replacement for Reggie Love. Especially with Michelle always gone on vacation and campaigning. This church is full of (and known for) sexual deviants of all kinds. Obama needs someone for company, especially since very few seem to want to see him in person anymore.
4. Obama feels it is his duty to be available at least occasionally for God so he can give God advice about how things should be run.