The bass synth lead is a big “hook” for this arrangement. Find a setting on your keyboard, or the patch itself, that limits pitch bending to 2 half steps, and slide into that note (notated in the synth pad / lead sheet music.)
D major is a bright key for a tenor worship leader but C major might be a little easier for your congregation to sing, especially if A Mighty Fortress is the opening song in your set – the lower key can help warm up the voices of your congregation!