Read: Philippians 2:12-13
…continue to work out your salvation with fear and trembling, for it is God who works in you to will and to act in order to fulfill his good purpose. Phil 2:12b-13
Work out your own salvation does not mean by your own effort, as some have interpreted it. The apostle is saying, now that I am no longer present with you, you don’t need to rely on my insights and counsel. Begin to walk without my assistance, for you have God in you, and that is all you need. In other words, stop leaning on me. Start applying these things yourselves. This is a necessary stage in Christian growth.
I recall teaching my oldest daughter how to drive. She had a learner’s permit that required that I be with her in the front seat of the car. As we were driving she would sometimes give me a questioning look as a driver pulled out in the road or something developed ahead of us. Then I’d say do this or that. She was relying on me, but the time would come when I moved out of the front seat and in faith committed her to what she had learned. From then on she had to work out her own salvation with fear and trembling, even with me right there with her in the back seat!