Judges 1:27
Neither did Manasseh drive out the inhabitants of Beth-shean and her towns, nor Taanach and her towns, nor the inhabitants of Dor and her towns, nor the inhabitants of Ibleam and her towns, nor the inhabitants of Megiddo and her towns: but the Canaanites would dwell in that land.
After entering Canaan Israel made only a partial conquest, with Manasseh failing to drive out the inhabitants of Beth-shean and her towns, Taanach and her towns, Dor and her towns, Ibleam and her towns, and Megiddo and her towns, so that the Canaanites continued to dwell in that land. In unbelief and love of ease the people settled down to enjoy the fruit of victories already won, gathering together in the portions already conquered instead of pushing forward to occupy new territory and take possession of the whole land. The failure was driven by convenience and self-interest, a stopping short of complete obedience.
By stopping short Israel left unfinished God's purpose to fully dispossess the inhabitants, to extend its territory under His care, to make Him known, and to banish heathen practices. This neglect was the beginning of departure from God and made it impossible for Him to fulfill to them His promise of blessing. Those left undriven would become a snare and a thorn, a trap and a source of affliction within the land. The same guilt rests on the church today when professed Christians congregate where they can enjoy gospel privileges and refuse to carry the message of salvation into regions beyond.