"But they were unfaithful to the God of their ancestors and prostituted themselves to the gods of the peoples of the land, whom God had destroyed before them." (1 Chronicles 5:25)
The genealogies of the Transjordan tribes follow. Reuben's line is noted with the explanation that though he was the firstborn, his rights were given to Joseph because he defiled his father's bed, and the leadership role went to Judah, from whom the ruler came. The tribe of Gad is enumerated. The half-tribe of Manasseh is listed. Together these tribes made war against the Hagrites and won because they cried out to God and trusted in him during the battle. They occupied the land until the exile.
But they were unfaithful to the God of their ancestors and prostituted themselves to the gods of the peoples of the land, whom God had destroyed before them. So the God of Israel stirred up the spirit of Pul king of Assyria, and he took them into exile. The pattern of Chronicles is established in microcosm in this chapter: faithfulness in battle brings victory; unfaithfulness to the covenant brings exile. The theological interpretation of history is the Chronicler's primary tool. The Catechism draws from this the principle that the covenant consequences of infidelity are real and historical, not merely spiritual abstractions (CCC 1964).
Brothers and sisters, they won the battle because they cried out to God and trusted in him. Then they lost the land because they prostituted themselves to the gods of the peoples they had defeated. Victory without ongoing faithfulness produces the exile that the victory was meant to prevent. Stay faithful after the victory as you were before it.
Lord God, keep us faithful after our victories as we are in our battles. Deliver us from the idolatry that follows success. Through Christ our Lord. Amen.