Joshua has a Blackmagic switcher with his Lenovo laptop for his church. He's trying to put words on the live feed, with a background using the Easy Worship software. But they say he needs a video card with dual HDMI ports. Leo says that's called "Chyron," and Lower Thirds. The ATEM Switcher should be able to do it, though, even without the Easy Worship software. In fact, the ATEM doesn't need a separate computer at all - It's turnkey, try taking that out of the mix. Leo also says that if you're using the software, try using the scripture verses as an alpha channel, so that all the text appears and nothing else. Then make the camera a downstream key. There should be an overlay setting on the ATEM that will allow you to then enable it through the switcher.
The Chatroom says there's youtube video on how to do it here - https://www.youtube.com/watch?v=4EifYkm3akE
Also, here's a lower third tutorial https://www.youtube.com/watch?v=Meb3U_CYgwQ