In our church they found that special events like concerts that took place IN the church, in the context that included some religious content, were a major way of drawing new people in.

What really worked was renting the city's main concert hall for a huge Xmas eve service with very professionally done music and invitations to local politicians and celebs. It also gave all the lesbian and gay Christians the chance to bring their whole families to a service in a place that didn't seem somehow scary (ooh, a gay church, how dark it must be inside!), and this led to much joy on all sides.