the word "rapture" is not in the bible but the teaching is.
it is most prominent in pauls writings,but i think alluded to elsewhere.
i believe that i shall be "caught up" but that is not a case of pride,as someone earlier suggested.christian teaching rather is that it is only by the undeserved favour of God that repentant sinners are saved.pride,is more likely the condition of unrepentant and rebellious people who think they dont need the forgiveness of God.
as to not knowing the timing of the second coming- assuming the rapture occurs before the great tribulation [the view i favour,without being dogmatic],it is true that the first part of that coming is of unknown date,whereas for those left behind may be expecting the second part in appx 7 yrs.