Fear and trembling is the attitude with which Christians are to pursue their ongoing sanctification. It involves a healthy fear of offending God and a righteous awe and respect for Him (Proverbs 1:7; Psalm 34:9; Isaiah 66:2), *not fear of God as if He is a tyrant who can't wait to punish you every time you mess up.
*That is the unhealthy fear of God that I had while growing up in the Roman Catholic church.
I was in a discussion on a different Christian forum in which the thread was entitled: "Is sanctification an event, a process, or both?" We had a very good discussion.
Many came to agree there is an initial sanctification in which believers are made holy in standing before God postionally in Christ, 1 Corinthians 6:11 - Such were some of you; but you were washed, but you
were sanctified, but you were justified
in the name of the Lord Jesus Christ.. 1 Corinthians 1:2 - To the church of God which is at Corinth, to those who
have been sanctified (past tense) in Christ Jesus..
Yet we also see progressive sanctification in which the reality of that holiness becomes more and more evident in our actions, words, thoughts, attitudes, and motives. 1 Thessalonians 4:3-4 - For this is the will of God, your
sanctification: that you should
abstain (present tense) from sexual immorality; that each of you should know how to possess his own vessel in sanctificationand honor. Hebrews 10:14 - For by one offering He has perfected forever those who are
being sanctified.
So becoming washed, sanctified and justified in Christ is a one time event, yet abstaining from sexual immorality (ongoing sanctification) is not a one time event.