Are there Bible teachings Christians can disagree on and some they cannot?
Yes. Scripture allows room for disagreement on many matters, but some teachings are absolute and cannot be compromised. Hebrews 11:6 is one: without faith it is impossible to please God, for anyone who comes to Him must believe that He exists and that He rewards those who diligently seek Him.
Les explains that Hebrews warns believers to guard against an evil heart of unbelief, not merely covetousness or immorality. He calls Hebrews 11:6 one of the two absolutes we must confront, saying it cannot be detoured around or compromised. While he tells people he does not get upset when they disagree with him on many scriptural things because there is room for disagreement, he insists some areas have no room for disagreement. Faith is such an absolute: without faith it is impossible to please God, and whoever comes to God must believe that He is and that He is a rewarder of those who diligently seek Him.
But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him.