Strengths are the first thing that we must tear down from the minds of people, to be able to teach a full gospel, if we do not knock down the strongholds first, the message will not stay in their minds. the word of God says in 2 Corinthians 10: 5

We demolish arguments and all pretensions that are set against the knowledge of God, and we take captive every thought to make it obedient to Christ