1 Corinthians 1:23

but we preach Christ crucified The Christian doctrine was the very reverse of what Jews and Greeks demanded. Instead of Messiah upon an earthly throne, triumphant over his enemies, instead of a skilful and original disputant, the Christian preachers speak of a condemned criminal. As a temporal Prince He had no pretensions to notice. To the title of philosopher, at least in the Corinthian sense of the term, He had no claim. His one argument was His Life and Death. What wonder if this doctrine were to the Jews an offence, and sheer nonsense in the ears of the inquisitive and argumentative Greek?

a stumblingblock The expression used here is the same as in the Septuagint version of Isaiah 8:14.