"The great tribulation" is a distinctly different from the kind of tribulation we experience in a general sense. There's a lot more Biblical material on this, but in the below passage Jesus speaks about it a bit.
Matthew 24:15-25
15When ye therefore shall see the abomination of desolation, spoken of by Daniel the prophet, stand in the holy place, (whoso readeth, let him understand
16Then let them which be in Judaea flee into the mountains:
17Let him which is on the housetop not come down to take any thing out of his house:
18Neither let him which is in the field return back to take his clothes.
19And woe unto them that are with child, and to them that give suck in those days!
20But pray ye that your flight be not in the winter, neither on the sabbath day:
21For
then shall be great tribulation, such as was not since the beginning of the world to this time, no, nor ever shall be.
22And except those days should be shortened, there should no flesh be saved: but for the elect's sake those days shall be shortened.
23Then if any man shall say unto you, Lo, here
is Christ, or there; believe
it not.
24For there shall arise false Christs, and false prophets, and shall shew great signs and wonders; insomuch that, if
it were possible, they shall deceive the very elect.
25Behold, I have told you before.