In his commentary on the book of Philippians, Dr. Clark said the following in reference to Philippians 1:16, 17, 18:
Verse 16 continues the sentence in verse 15. [Philippians 1:15, 16]. Those who had been emboldened to preach publicly were divided into two groups. Some preached from good motives; some did not. The former loved both Paul and the Gospel. They knew and were inspired by the fact that Paul was completely devoted to the defense of the Gospel.
The word for defense is apologia: in technical theology, apologetics. Some misguided Christians today repudiate argumentation. The New Testament does not. Not only is apologia in 1 Peter 3:15; it is also in Acts 22:1, 1 Corinthians 9:3, 2 Corinthians 7:11, and Philippians 1:7, as we recently saw. Mark 9:10 has the disciples "questioning one with another" (suzeteo)--they were acting properly. In Mark 12:28 a scribe had heard Jesus arguing with the Sadducees. Acts 6:9 has some people disputing with Stephen and clearly Stephen disputed with them, as 6:10 [Acts 6:10] very forcefully indicates. Barnabus in Acts 9:29 defends the recently converted Paul by telling the suspicious disciples that Paul disputed against the Grecians. Well, these verses should be enough to silence those who think that a Christian should not argue.
Dr. Gordon H. Clark. Philippians. (Hobbs: The Trinity Foundation, 1996). Page 28.
See also: Philippians.
For liberals and those who promote ecumenical reunion above Scriptural truth, arguing and polemics are the unforgivable sin for Christian fellowship. But the reality is that those who are teaching heresy or those who contend out of selfish ambition are the ones who are creating the divisions. The faith once delivered to the saints is to be "earnestly" contended for. (Jude 1:3).