what Would be purpose For Church to go thru Great Tribulation Period?

The hour:

Strong's Number: 5610 w¸ra
Original Word Word Origin
w¸ra apparently a primary word
Transliterated Word Phonetic Spelling
Hora ho'-rah
Parts of Speech TDNT
Noun Feminine 9:675,1355
Definition
a certain definite time or season fixed by natural law and returning with the revolving year
of the seasons of the year, spring, summer, autumn, winter
the daytime (bounded by the rising and setting of the sun), a day
a twelfth part of the day-time, an hour, (the twelve hours of the day are reckoned from the rising to the setting of the sun)
any definite time, point of time, moment

Translated Words
KJV (108) - hour, 89; misc, 5; season, 3; time, 11;
NAS (106) - hour, 84; hours, 3; late, 2; moment, 3; once, 3; short, 1; time, 6; while, 4;

so it can be a point of time or a definite time.

Rev. 2: 25 But that which ye have already hold fast till I come.
26 And he that overcometh, and keepeth my works unto the end, to him will I give power over the nations:
27 And he shall rule them with a rod of iron; as the vessels of a potter shall they be broken to shivers: even as I received of my Father.
28 And I will give him the morning star.
29 He that hath an ear, let him hear what the Spirit saith unto the churches.

These are promised a place to rule in the milenial. 2 Tim. 2: 12If we suffer, we shall also reign with him: if we deny him, he also will deny us. Again we will reign if we suffer with Him that includes Paul and Timothy, that will be the Milenial Kingdom.