nabil added a post in a topic Help With Big Glass Doors
here is my take on doors like this.
-choose nice straight grain for your rails and stiles...........rift/quarter sawn. This helps prevent any racking/bowing of the frame.
-Use mortise and tenon joinery to put the frame together. Personally I would use a cope and stick bit set along with M&T.
-Glass should have a 1/16" clearance all around. I normally bed the glass inside the rabbet with some clear silicone.
-If you still feel the frame is not ridgid enough you may want to add a muntin and split the lites into 4.