Why God's people suffer
Deuteronomy 8:1-6
1 All the commandments which I command thee this day shall ye observe to do, that ye may live, and multiply, and go in and possess the land which the LORD sware unto your fathers.
 And thou shalt remember all the way which the LORD thy God led thee these forty years in the wilderness, to humble thee, to prove thee, to know what was in thine heart, whether thou would keep his commandments, or no.
 And he humbled thee, and suffered thee to hunger, and fed thee with manna, which thou knew not, neither did thy fathers know; that he might make thee know that man doth not live by bread only, but by every word that proceeds out of the mouth of the LORD doth man live.
 Thy raiment waxed not old upon thee, neither did thy foot swell, these forty years.
 Thou shalt also consider in thine heart, that, as a man chastens his son, so the LORD thy God chastens thee.
6  Therefore thou shalt keep the commandments of the LORD thy God, to walk in his ways, and to fear him.
...
16   Who fed thee in the wilderness with manna, which thy fathers knew not, that he might humble thee, and that he might prove thee, to do thee good at thy latter end;

2Cor 12:7  And that I might not be exalted by the exceeding greatness of the revelations, there was given to me a thorn for the flesh, a messenger of Satan that he might buffet me, that I might not be exalted.
 8 For this I thrice besought the Lord that it might depart from me.
 9 And he said to me, My grace suffices thee; for my power is perfected in weakness. Most gladly therefore will I rather boast in my weaknesses, that the power of the Christ may dwell upon me. (DBY)

Psalm 13:1-3
How long will You forget me?
O LORD, for'ere it seems to be.
How long You hide Your face from me
while I in darkness grope for Thee?
2 How long shall I counsel my soul,
My heart daily having sorrow?
How long shall my adversary
still be exalted over me?
3  Look carefully and answer me,
O Lord my God, enlighten me,
lest I should sleep the sleep of death,
while for my soul, I get no rest.

The Sands of Time are Sinking  by Anne Cousin stanza 8
But flowers need nights' cool darkness,
the moonlight and the dew;
So Christ, from one who loved it,
His shining oft withdrew:
And then, for cause of absence
my troubled soul I scanned
But glory shadeless shineth
in Immanuel’s land.

1John 2:3-6 
3 And hereby we know that we know him, if we keep his commandments.
 4 He that says, I know him, and does not keep his commandments, is a liar, and the truth is not in him;
 5 but whoever keeps his word, in him verily the love of God is perfected. Hereby we know that we are in him.
 6 He that says he abides in him ought, even as *he* walked, himself also so to walk. (DBY)

Psalm 17:3 
You have proved my heart, You have visited
in the night; You have examined me.
You're finding nothing. That which I have thought,
out from my mouth, it shall not proceed.

 But he answering said, It is written, Man shall not live by bread alone, but by every word which goes out through God's mouth. (Mat 4:4 DBY)

James 2:8-13 
 8 If indeed ye keep the royal law according to the scripture, Thou shalt love thy neighbor as thyself, ye do well.
 9 But if ye have respect of persons, ye commit sin, being convicted by the law as transgressors.
 10 For whoever shall keep the whole law and shall offend in one point, he has come under the guilt of breaking all.
 11 For he who said, Thou shalt not commit adultery, said also, Thou shalt not kill. Now if thou dost not commit adultery, but kills, thou art become transgressor of the law.
 12 So speak ye, and so act, as those that are to be judged by the law of liberty;
 13 for judgment will be without mercy to him that has shown no mercy. Mercy glories over judgment. (DBY)

Deut 7:17   Ye shall diligently keep the commandments of the LORD your God, and his testimonies, and his statutes, which he hath commanded thee.
18  And thou shalt do that which is right and good in the sight of the LORD: that it may be well with thee, and that thou mayest go in and possess the good land which the LORD sware unto thy fathers,

1 Corinthians 10:1-13  
For I would not have you ignorant, brethren, that all our fathers were under the cloud, and all passed through the sea;
 2 and all were baptized unto Moses in the cloud and in the sea;
 3 and all ate the same spiritual food,
 4 and all drank the same spiritual drink, for they drank of a spiritual rock which followed them: (now the rock was the Christ;)
 5 yet God was not pleased with the most of them, for they were strewed in the desert.
 6 But these things happened as types of us, that we should not be lusters after evil things, as they also lusted.
 7 Neither be ye idolaters, as some of them; as it is written, The people sat down to eat and to drink, and rose up to play.
 8 Neither let us commit fornication, as some of them committed fornication, and fell in one day three and twenty thousand.
 9 Neither let us tempt the Christ, as some of them tempted, and perished by serpents.
 10 Neither murmur ye, as some of them murmured, and perished by the destroyer.
 11 Now all these things happened to them as types, and have been written for our admonition, upon whom the ends of the ages are come.
 12 So that let him that thinks that he stands take heed lest he fall.
 13 No temptation has taken you but such as is according to man's nature; and God is faithful, who will not suffer you to be tempted above what ye are able to bear, but will with the temptation make the issue also, so that ye should be able to bear it. (1Co 10:1-13 DBY)

1Peter 1:6-7 
6 Wherein ye exult, for a little while at present, if needed, put to grief by various trials,
 7 that the proving of your faith, much more precious than of gold which perishes, though it be proved by fire, be found to praise and glory and honor in the revelation of Jesus Christ:
 (1Pe 1:6-7 DBY)

2Cor 1:3-7 
3 Blessed be God, even the Father of our Lord Jesus Christ, the Father of mercies, and the God of all comfort;
 4 Who comforts us in all our tribulation, that we may be able to comfort them which are in any trouble, by the comfort wherewith we ourselves are comforted of God.
 5 For as the sufferings of Christ abound in us, so our consolation also abounds by Christ.
 6 And whether we be afflicted, it is for your consolation and salvation, which is effectual in the enduring of the same sufferings which we also suffer: or whether we be comforted, it is for your consolation and salvation.
 7 And our hope of you is stedfast, knowing, that as ye are partakers of the sufferings, so shall ye be also of the consolation.  (2Co 1:3-7 KJV)

Colossians 1:24  Now I rejoice in my sufferings for your sake, and fill up on my part that which is lacking of the afflictions of Christ in my flesh for his body's sake, which is the church; (Col 1:24 ASV)

10  That I may know him, and the power of his resurrection, and the fellowship of his sufferings, being made conformable unto his death; (Philip 3:10 KJV)

Rev 3:19-22 
19 As many as I love, I rebuke and chasten: be zealous therefore, and repent.
 20 Behold, I stand at the door, and knock: if any man hear my voice, and open the door, I will come in to him, and will sup with him, and he with me.
 21 To him that overcomes will I grant to sit with me in my throne, even as I also overcame, and am set down with my Father in his throne.
 22 He that hath an ear, let him hear what the Spirit saith unto the churches. (Rev 3:19-22 KJV)

Heb 12:5-13 
5 And ye have forgotten the exhortation which speaks unto you as unto children, My son, despise not thou the chastening of the Lord, nor faint when thou art rebuked of him:
 6 For whom the Lord loveth he chastens, and scourges every son whom he receives.
 7 If ye endure chastening, God deals with you as with sons; for what son is he whom the father chastens not?
 8 But if ye be without chastisement, whereof all are partakers, then are ye bastards, and not sons.
 9 Furthermore we have had fathers of our flesh which corrected us, and we gave them reverence: shall we not much rather be in subjection unto the Father of spirits, and live?
 10 For they verily for a few days chastened us after their own pleasure; but he for our profit, that we might be partakers of his holiness.
 11 Now no chastening for the present seems to be joyous, but grievous: nevertheless afterward it yields the peaceable fruit of righteousness unto them which are exercised thereby.
 12 Wherefore lift up the hands which hang down, and the feeble knees;
 13 And make straight paths for your feet, lest that which is lame be turned out of the way; but let it rather be healed. (Heb 12:5-13 KJV)

For in many things we offend all. If any man offend not in word, the same is a perfect man, and able also to bridle the whole body. (Jam 3:2 KJV)

Matt 6:21-23 
21 For where your treasure is, there will your heart be also.
 22 The light of the body is the eye: if therefore thine eye be single, thy whole body shall be full of light.
 23 But if thine eye be evil, thy whole body shall be full of darkness. If therefore the light that is in thee be darkness, how great is that darkness! (Mat 6:21-23 KJV)