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 to help the church. The Holy Spirit gives these gifts to Christians after they come to believe 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. Other scholars believe all the gifts of the Spirit are still available to help all Christians throughout the church history. (See: [[rc://en/tw/dict/bible/kt/faith]])
In this chapter, Paul refers to the return of Christ 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 the Corinthians 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 allowed his Messiah to be crucified. (See: [[rc://en/ta/man/translate/figs-metaphor]])