And the fear of the Lord fell upon all the kingdoms of the lands that were around Judah, and they made no war against Jehoshaphat.
2 Chronicles 17:10
This was the blessing of God coming to His obedient people. As Judah obeyed God and Jehoshaphat restored the worship of the Lord in Jerusalem, taking great measures to provide for the teaching of God's Law throughout Judah, God granted peace. Judah became powerful and prosperous. Peace came around the nation as an outcome of their faithfulness to the Lord and to His Law again.
God blessed His people when they simply obeyed the covenant again. The nation prospered under God as His covenant people. God kept His Word and His people worshiped Him, turned to God in faith, and taught His truth to the next generation. It took a God-fearing leader to get this revival started, but God used king Jehoshaphat to strengthen His people.
Obedience to the Lord is the only path to real peace. Believing Him and trusting Him are the sources of security. God's blessing comes by faith in what He has done, trusting God, so that we might have the ability to obey His Word, do His will, and know His peace.