Our culture lives in the air of tolerance. Tolerance used to mean, “I disagree with what you believe but will defend your right to believe it.” Now tolerance means, “No one can know for certain he holds the truth. Don’t claim absolute truth.”
This ambivalent view of truth has affected how the church views belief and doctrine. Churches have a hard time holding to vital doctrines. But Scripture attacks this lack of backbone. Scripture declares that we can know the truth and what we believe does matter. It is important. So important that:
People go to hell for believing the wrong things. “But even if we or an angel from heaven should preach a gospel other than the one we preached to you, let him be eternally condemned.” (Gal 1:8 NIV).
People within the church should be corrected when they believe the wrong things. “[An elder] must hold firmly to the trustworthy message as it has been taught, so that he can encourage others by sound doctrine and refute those who oppose it” (Titus 1:9) NIV
People are sometimes to be kept out of your house for believing the wrong things. “Anyone who runs ahead and does not continue in the teaching of Christ does not have God; whoever continues in the teaching has both the Father and the Son. If anyone comes to you and does not bring this teaching, do not take him into your house or welcome him” (2 John 9-10)
From Why We’re Not Emergent by Kevin DeYoung and Ted Kluck, p.112
I would also add:
Jesus rebukes churches for tolerating false beliefs. “Nevertheless, I have a few things against you: You have people there who hold to the teaching of Balaam, who taught Balak to entice the Israelites to sin by eating food sacrificed to idols and by committing sexual immorality. Likewise you also have those who hold to the teaching of the Nicolaitans. Repent therefore! Otherwise, I will soon come to you and will fight against them with the sword of my mouth” Revelation 2:14-16.
So as we love others, let us love them in the truth.