Can someone PLEASE explain episode 52 of Red vs Blue?

The one with Chuch time-traveling. I saw it long ago and remember not understand wtf was going on.. haha. I'm rewatching them as the series is coming to an end. Can someone PLEASE explain everything. I SORT OF get it up until the part where Church tells himself that it's ok to free Tex. Wouldn't church have already done that? Also, the time-traveling church we have been watching.. Why wouldn't he have been the most recent church? I am so confused... hahaha.