Show me a reference versus for that, please.
Philippians 2:12-18 (KJ)
12 Wherefore, my beloved, as ye have always obeyed, not as in my presence only, but now much more in my absence, work out your own salvation with fear and trembling.
13 For it is God which worketh in you both to will and to do of his good pleasure.
14 Do all things without murmurings and disputings:
15 That ye may be blameless and harmless, the sons of God, without rebuke, in the midst of a crooked and perverse nation, among whom ye shine as lights in the world;
16 Holding forth the word of life; that I may rejoice in the day of Christ, that I have not run in vain, neither laboured in vain.
17 Yea, and if I be offered upon the sacrifice and service of your faith, I joy, and rejoice with you all.
18 For the same cause also do ye joy, and rejoice with me.
When Paul was on his second mission trip and talking to the Phillippians and he was talking about "work out your salvation" it was not a reference to "earn ones salvation" but his expression of one's salvation in spiritual growth and development. Salvation is a gift received once and for all, it is however expressed as an ongoing process where the believer is actively involved. "Fear and trembling" is not doubt and anxiety but in reference to active reverence and spinelessness purpose of response to God's Grace.