The Land of Canaan belonged to the Israelites as it had been given to Abraham and promised to his seed as an everlasting possession. 

The Philistines, Amorites and others who inhabited the land at the time when Moses under Divine direction led the Israelites out of Egypt were a semi-barbarous race whose sins and iniquities had come to the full. Because they had become so depraved, the Lord saw that it would be best to destroy them. Let us suppose that a people occupying the land of Canaan today were to become so degraded and corrupt that they were a menace to civilization, robbing and massacring innocent people, and in all ways being obnoxious both to themselves and to other nations. 

Would it be thought an unwise, unjust or unloving arrangement for the Lord to cause their removal and entire destruction in order to make way for the establishment of the Israelites in their own land? Many of the prophecies of the Scriptures clearly indicate such a development of affairs, and that the Israelites have been gathered back into their own country from the uttermost parts of the earth. (See Jeremiah 32:36-44) Reverting to the question: we see women and children, young and old, dying off in multitudes every day with but very little evidence of the Lord’s love in any direction. However, the Lord has arranged in His plan of salvation a time and a way when all the races shall be delivered from the death conditions. Isaiah 35:8-10, Revelation 21:3-5.

Additional Resource:
Christian Questions Podcast Episode #1218: “Is God’s Wrath Stronger Than His Love? (Part I)”
Examining God’s harsh Old Testament judgment in light of His plan
Preview Video
CQ Rewind Show Notes