Are we polluting the perfect pure message of the Gospel?
1. Paul's introduction. (v1,2). Paul establishes his commission from God. The message (v3-5). The free grace of God, which rescues us from sin - no human effort. It is God's message, and it is not open for change. It is not a smorgasbord.
2. Paul is astonished they have contaminated the message. (v6,7). They are deserting God. (Chapter 6 :12 - need to keep Jewish customs). (Like changing the Mona Lisa painting). The Gospel is attacked even today by adding to and subtracting from it.
3. Getting the message right (v8-10). (a) Focus on the message of the Gospel, and not the messenger. The messenger is not more important than the Gospel. We don't believe something because of who they are, then be careful (even an angel). Check the message against the Bible. (b) Ask question, whom am I trying to please. (v10). There is always some discomfort in the Gospel, as it challenges us - we must not water this down.
