, ▁bishop ▁of ▁Na um burg - Ze itz , ▁he ▁was ▁installed ▁there ▁on ▁ 2 0 ▁January ▁ 1 5 4 2 , ▁though ▁in ▁opposition ▁to ▁the ▁chapter , ▁by ▁the ▁Prince - elect or ▁of ▁Sax ony ▁and ▁Luther . ▁His ▁position ▁was ▁a ▁pain ful ▁one , ▁and ▁he ▁long ed ▁to ▁get ▁back ▁to ▁Mag de burg , ▁but ▁was ▁persu aded ▁by ▁Luther ▁to ▁stay . ▁After ▁Luther ' s ▁death ▁( 1 5 4 6 ) ▁and ▁the ▁Battle ▁of ▁M ühl berg ▁( 1 5 4 7 ) ▁he ▁had ▁to ▁yield ▁to ▁his ▁rival , ▁Julius ▁von ▁P flug , ▁and ▁ret ire ▁to ▁the ▁protection ▁of ▁the ▁young ▁du ke ▁of ▁We imar . ▁Here ▁he ▁took ▁part ▁in ▁found ing ▁J ena ▁University ▁( 1 5 5 8 ); ▁opposed ▁the ▁" A ugs burg ▁Inter im " ▁( 1 5 4 8 ); ▁super int ended ▁the ▁publication ▁of ▁the ▁J ena ▁edition ▁of ▁Luther ' s ▁works ; ▁and ▁deb ated ▁on ▁the ▁freedom ▁of ▁the ▁will , ▁original ▁sin , ▁and , ▁more ▁notice ably , ▁on ▁the ▁Christian ▁value ▁of ▁good ▁works , ▁in ▁regard ▁to ▁which ▁he ▁held ▁that ▁they ▁were ▁not ▁only ▁useless , ▁but ▁pre jud icial ▁in ▁the ▁matter ▁of ▁man ' s ▁salv ation . ▁He ▁ur ged ▁the ▁separation ▁of ▁the ▁High ▁Luther an ▁party ▁from ▁Mel anch th on ▁( 1 5 5 7 ), ▁got ▁the ▁Sax on ▁du