When you read the words “fear and trembling”, do not think it speaks about effort.
In fact it actually means there is no human effort involved. Rather it speaks about the Holy Spirit’s power.
1 Corinthians 2:3-4
3 I came to you in weakness and fear, and with much trembling. 4 My message and my preaching were not with wise and persuasive words, but with a demonstration of the Spirit’s power.
It’s not by human persuasion but by the workings of the Holy Spirit. That is how you work out your salvation. It’s not by human effort but by the power of the Holy Spirit.
if so, pray tell me what does Paul goes on to say all his obedience in the Law is dung and that all that counts for him, is the righteosuness that comes from faith in Jesus In the next chapter?