In partial rapture, the first rapture according to readiness is not to protect us from the Tribulation, but to be received up because we were ready to be taken. Think of this like a balloon tied down to a railing of the world. If the Christian is still controlled by the world, he is not willing to be released.

Those who kept the word of His patience escape the hour of trial, who were watchful and prayerful to escape all these things that shall come to pass. It is better to be taken than left (Matt. 24.40-42). Spiritual Christians are raptured alive at the time of the start of the Tribulation. Christians during the Tribulation who are martyred are resurrected and raptured 3.5 days after they go to rest.

If you find yourself in the Tribulation realize the reason you were not taken was because you were still a babe in Christ, a fleshly not a spiritual Christian. Paul said there are spiritual and carnal Christians. Don't take away this hope for the Church.

Also when you are in the Tribulation and a couple million are first taken, raptured alive, will you accuse the brethren day and night? (Rev. 12.10)

I am not saying everyone who is like this is not a Christian.

http://www3.telus.net/trbrooks/Partial_rapture.htm