He who is not with Me is against Me… Luke 11:23
For he who is not against us is on our side. Mark 9:40
These two sayings by Jesus seem at first glance to be contradictory. What do we do with such passages?
Since God cannot contradict Himself, His Word cannot contradict itself.
So, where there appears to be a contradiction, since there cannot be any contradictions in God’s Word, we must dig deeper to understand the apparent contradiction. There are two keys that unlock this apparent contradiction.
The first is discerning what is meant by being for or against. It is possible for believers to be in agreement or disagreement both in essential matters and in non essential matters.
That being true, we can easily understand that Jesus was saying that if one is not for Him in essentials (e.g., the gospel), one is truly against Him. Yet we may differ on lesser matters and still be His disciples (e.g., modes of baptism).
The second key is that in Luke 11:23, this issue is being for or against Christ Himself. Not being for Christ is tantamount to being against Christ. In Mark 9:40 the issue is not being for or against Christ, but being for or against others of Christ’s disciples. While it is desirable that Christ’s disciples agree as much as possible, we are not always in agreement with one another. Disagreements between believers doesn’t mean we are on opposing sides concerning Christ.