Why are there trials, tribulations and persecutions?

Through trial and persecution the glory--the character--of God is revealed in His chosen ones. . . . They follow Christ through sore conflicts; they endure self-denial and experience bitter disappointments; but thus they learn the guilt and woe of sin, and they look upon it with abhorrence. CC p.360

There is not a blessing which God bestows upon man, nor a trial which He permits to befall him, but Satan both can and will seize upon it to tempt, to harass and destroy the soul, if we give him the least advantage. Therefore however great one's spiritual light, however much he may enjoy of the divine favor and blessing, he should ever walk humbly before the Lord, pleading in faith that God will direct every thought and control every impulse. PP p.421

Not in freedom from trial, but in the midst of it, is Christian character developed. Exposure to rebuffs and opposition leads the follower of Christ to greater watchfulness and more earnest prayer to the mighty Helper. Severe trial endured by the grace of God develops patience, vigilance, fortitude, and a deep and abiding trust in God. It is the triumph of the Christian faith that it enables its followers to suffer and be strong; to submit, and thus to conquer; to be killed all the day long, and yet to live; to bear the cross, and thus to win the crown of glory. AA p.467

Trials patiently borne, blessings gratefully received, meekness, kindness, mercy, and love, habitually exhibited, are the lights that shine forth in the character before the world, revealing the contrast with the darkness that comes of the selfishness of the natural heart. CC p.59

The dark hours of trial are to come to every one as a part of his education for higher work, for more devoted, consecrated effort. The storm was not sent upon the disciples to shipwreck them, but to test and prove them, individually. . . . OHC p.56 

The Lord permits trials in order that we may be cleansed from earthliness, from selfishness, from harsh, unchristlike traits of character. He suffers the deep waters of affliction to go over our souls in order that we may know Him and Jesus Christ whom He has sent, in order that we may have deep heart longings to be cleansed from defilement, and may come forth from the trial purer, holier, happier. Often we enter the furnace of trial with our souls darkened with selfishness; but if patient under the crucial test, we shall come forth reflecting the divine character. When His purpose in the affliction is accomplished, "He shall bring forth thy righteousness as the light, and thy judgment as the noonday." Ps. 37:6. COL p.174

If the tempted soul endures the trying process, and self does not awake to life to feel hurt and abused under the test, that probing knife reveals that the soul is indeed dead to self, but alive unto God. CC p.322

Many who do not shrink from active warfare for their Lord are driven by ridicule to deny their faith. By associating with those whom they should avoid, they place themselves in the way of temptation. They invite the enemy to tempt them, and are led to say and do that of which under other circumstances they would never have been guilty. The disciple of Christ who in our day disguises his faith through dread of suffering or reproach denies his Lord as really as did Peter in the judgment hall. CC p.321

Walk and work in the spirit of Christ. Stand ever on guard, for temptations will come, and the Lord's disciples are to be as true as steel to principle. . . . TMK p.128

Shall we be less willing to endure conflict and toil, and to make earnest efforts and great sacrifices for the infinite treasure, which passes all estimate in value, and the duration of life which will measure with the Infinite? Can Heaven cost us too much? Faith and love are golden treasures, elements that are greatly wanting among God's people. RH, September 16, 1873

The trials of life are God's workmen to remove the impurities, infirmities, and roughness from our characters, and fit them for the society of pure, heavenly angels in glory. The fire will not consume us, but only remove the dross, and we shall come forth seven times purified, bearing the impress of the Divine. ML 92

Christ will remove every pretentious cloak. No mingling of the true with the spurious can deceive him. "He is like a refiner's fire," separating the precious from the vile, the dross from the gold.  RH, November 8, 1906

KEYS TO ABBREVIATION:
RH - Review and Herald
CC - Conflict and Courage
TMK - That I May Know Him
COL - Christ Object Lesson
AA - The Acts of the Apostles
OHC - Our High Calling
PP - Patriarchs and Prophets
ML - My Life Today
RH - Review and Herald