The dominating theme in 1 Chronicles is the Davidic Covenant, the receiving of which was the most important event in David's life. God promised to give him an eternal kingdom, and He formalized that promise by making a covenant with him. The writer repeated three times that David's descendants would be God's instruments for bringing salvation to the nations.
The Chronicler referred to the Davidic Covenant seven times in his book (1 Chron. 17:11-14; 22:8-13; 28:6-7; 2 Chron. 6:8-9, 16; 7:17-18; 13:5; 21:7). Many students of Chronicles have regarded the Davidic Covenant as the heart of these books because it established David's kingly line with promises that relate to the temple and the priesthood. The temple and the priesthood are two major themes of these books. God brought them under Davidic rule forever, as the Chronicler revealed.
Another unifying theme is the steps taken toward the building of the temple.
"These include identification of the builder (ch. 17), the necessary political conditions (18-20), site (21), materials and plans (22, 28-29), and the personnel (the primary layer in 23-27)."56