There are so many choices these days when addressing your keyboard needs for modern worship. Shell out say $3,000 for a synth by Nord, Yamaha, or Roland. Or, use your laptop and a controller like Axiom Pro or Studio Logic. I get a lot of questions about this topic, so I thought I would give you my thinking in hopes it aids in deciding for you the best option.
When an acoustic guitarist can spend $3,000 simply on a nice professional Taylor or Martin to lead worship with, the range in price is such that $500 might sound terrible while $5,000 terrific when you talk about wood, manufacturing, and the pickup electronics. I am here to say that you might feel less cool using a controller, but the geeky-ness of a laptop/iPad setup means for about $1,500 you can sound as good as a $3,300 workstation. If you already own a laptop, it might be less than that!