The original temptation was framed “Did God actually say…?” (Genesis 3:1 ESV). Throughout biblical and church history, false doctrine surfaces whenever God’s Word is questioned and other sources of doctrine/teaching are embraced. Evangelical Christianity believes that the Bible is the supreme and final authority in matters of faith and conduct. The Bible is what God actually says. False doctrine/teaching is departing from what the Bible affirms. Not all doctrinal matters have the same critical importance and we must practice what Al Mohler calls “theological triage” (see my post on “How do we decide whom we can work with”). But first-level doctrines define Christianity and departure from the Bible’s teaching on these matters results in a different religion. So false doctrine is an important matter.
False doctrine/teaching is a prominent theme in Paul’s letters to his church-planting partners, Timothy and Titus, yet we never find the phrase “false doctrine” or “false teaching.” He does describe it as “what is falsely called knowledge” (1 Timothy 6:20). Paul simply refers to the false teaching as a “different doctrine” (1 Timothy 1:3, 6:3) or sums it up as “whatever else is contrary to sound doctrine” (1 Timothy 1:10). In Galatians 1:6-9, Paul warns against a “different gospel.” There is an authoritative message of the Apostles that is not to be changed and is to be guarded and passed on to others. A “different gospel” or a “different doctrine” is to be avoided and rebuked vigorously.