Romans 16:17 amp

I appeal to you, brethren, to be on your guard concerning those who create dissensions and difficulties and cause divisions, in opposition to the doctrine (teaching) which you have been taught. (I warn you to turn aside from them, to) avoid them. 

Paul warns us to be on guard and avoid people who would cause dissensions.  The devil knows that a house divided does not conquer but is conquered.  If the devil is allowed to impart false doctrine unto the people and divide the church, we cannot be the change for the good.  The church is a force for God and can overcome all evils when working together according to the word.