...so that the priests could not stand to minister because of the cloud, for the glory of the LORD filled the house of God.
2 Chronicles 5:14
The dedication of the temple that Solomon built was quite literally a glorious event. The temple was filled with the glory of the Lord as a thick cloud rolled in over the temple mount. The fog was so thick that the priests could not do their duties. Temple operations were suspended as God took up residence in the temple, demonstrating His glory in a unique and very powerful way. Just as a cloud had led Israel day by day in the wilderness, so now, in the new temple in Jerusalem, God celebrated by this display of His presence with the people. He made Himself know through this very memorable manifestation of His glory.
God is pleased when His people worship Him and obey Him. When Israel sacrificed to build for Him this temple, God responded with the blessing of His presence. He is near those who worship Him. He will make Himself known to those who obey, follow, sacrifice, and worship Him.
I think the way this passage parallels Israel's history shows us something. God will make Himself known in familiar ways. To those Israelites in Jerusalem, this was the historical display of His glory. They knew from Torah that God led from a cloud. And now the new temple is filled with an impenetrable cloud of His glory as the ark is brought to the Most Holy Place. Just as the wilderness generation was aware of God's presence by the cloud, so the First Temple generation would be confident of God's presence through this manifested display of His glory. God confirmed His word and their work through showing His glory at the temple.