David wanted to bring the ark to Jerusalem to honour the Lord and confirm that he is the legitimate and blessed king of Israel.1 Since the ark represented the Lord’s rule and presence (see 1 Chronicles 28:2), it was appropriate for the ark to be in the capital city, religion and politics combined. The presence of the ark in Jerusalem would affirm that the will of the Lord was to be the central focus of David’s kingdom and he alone was to be worshipped in Israel.2 Finally, it legitimized David as God’s king by connecting him very directly with the Lord.3
2 And David arose and went with all the people who were with him from Baale-judah to bring up from there the ark of God, which is called by the name of the LORD of hosts who sits enthroned on the cherubim.