1 Corinthians 1:22 (ESV)

22 For Jews demand signs and Greeks seek wisdom,

Paul divides people into two groups: Jews and Gentiles (Gentiles refers to all the non-Jews who lived in the Roman Empire). Jews want to see signs. More than once, the Jewish leaders had tested Jesus, asking him to prove his authority with a sign from heaven (Mark 8:11; Luke 11:16; John 6:30). The Gentiles, on the other hand, seek wisdom. They are impressed (and blinded) by the philosophical arguments of their debaters (see 1 Corinthians 1:20).