Some reasons people do not go up in the rapture
They do not want to give up a sin such as unforgiveness or one they like doing so much.
They know about Jesus but do not have a personal relationship with Him (Jn17:3).
The do not serve The kingdom of God but serve the denomination.
They are comprised with worldly things (Do not pursue Holiness).
Deliberately do not preach a correct Gospel (it might offend people).
Ignore the guidance of The Holy spirit so do not live as God requires them to live. (He is the guide to The Kingdom of God so ignore His guidance at your peril).
Do not look for the return of Jesus so are not expecting it.
Deliberately do not do the work of The Kingdom
The know The Bible but deliberately do not do what it says to do such as evangelism, deliverance, discipling, meditating on it etc.
These are from what Jesus told people or what The Bible points as required for Christian living.
If you are game have a look at the following book detailing problems with the church