Sentence:  If Bultmann 's own definition of myth is strictly adhered to ( and it is interesting that this is almost never done by those who make such pronouncements ) , the evidence is overwhelming that he does not at all exaggerate the extent to which the mythological concepts of traditional theology have <WSD>become</WSD> incredible and irrelevant . 
Meaning of the word marked with <WSD> tags:  enter or assume a certain state or condition