"work out your own salvation with fear and trembling"
The Bible presents three kinds of salvation: the initial salvation from the penalty of sin, progressive salvation from the power of sin and ultimate salvation from the presence of sin. Here we have the second of the three, salvation of a church from sin in its midst. This is the salvation of the church’s ministry due to division.
"work out your own salvation "
Paul is saying here, "I cannot get out of jail at this time so you must work out the salvation of the church from this church split." "Salvation" here is the corporate salvation of the church at Philippi. This is salvation from division, pride and selfishness.
"Work out" has the idea of bringing to completion, to a conclusion. Paul is saying, "don’t stop half way when it comes to divisions in the church. Clean it up." Everyone was displaying their sin capacity: "I think that Euodias is right." "Well, I think Syntyche is right!" The church took the lid off the garbage can. It was an ugly scene. They were not winning people to Christ; they were operating a religious debating society to determine who was right. Notice that nothing is said of working for your salvation. There is not one line in the Bible to support that.
"with fear and trembling"
This phrase means "don’t attack the problem heavy handed." If they use the heavy hand approach it will split the church. A general practitioner cannot perform brain surgery. Care must be taken when people hold strong differences of opinion. This is just the opposite of what was happening in Philippi.
Approach the resolution of this problem "with fear and trembling" for fear of bungling the job. People are sensitive and can be hurt very easily. A situation like this requires kid gloves. Many people wear their feelings on their sleeve. They have both real and imaginary hurts. Everyone likes to be appreciated and noticed. They want to feel they are an asset.
Principle: It takes maturity and skill to handle deep divisions among people.
Application: Most divisions are attitudinal. It was said of the Lord, "For even the Son of Man did not come to be served, but so serve, and to give His life a ransom for many" (Mark 10:45). That is a major attitude! But, alas, that is not the attitude of most of us. We want people to cater to us. We want them to be nice to us. But we do not want to go out of our way to minister to them. The attitude of our Savior was to give in a self-sacrificing way.