Some translations set each line of poetry farther to the right than the rest of the text to make it easier to read. The ULB does this with the words of verse 19, which are from the Old Testament.
Spiritual gifts are specific supernatural abilities that the Holy Spirit gives to Christians after they come to faith in Jesus. Paul lists spiritual gifts in Chapter 12. Some scholars believe the Holy Spirit gave some of these gifts only in the early church to help establish the developing church. (See: [[rc://en/tw/dict/bible/kt/faith]])
In this chapter, Paul refers to the return of Christ to the earth using two different phrases: "the revelation of our Lord Jesus Christ" and "the day of our Lord Jesus Christ." (See: [[rc://en/ta/man/translate/figs-idiom]])
Paul uses rhetorical questions to scold them for dividing into factions and for relying on human wisdom. (See: [[rc://en/ta/man/translate/figs-rquestion]])
A stumbling block is a rock people stumble over. Here it means the Jews find it hard to believe that God would allow his Messiah to be crucified. (See: [[rc://en/ta/man/translate/figs-metaphor]])