John 8:43
Why do ye not understand my speech? even because ye cannot hear my word — Jesus explains their incomprehension: they do not understand his speech (dialektos, language, way of speaking) and cannot hear his word (logos). The distinction between understanding speech and hearing the word is important: they have ears but cannot receive his message. The reason is spiritual: without faith, the ear remains closed. Jesus's language is the language of heaven; those rooted only in the world cannot comprehend it.