Bhagavad-gita is the widely read theistic science

Start with SB 6.3.20-21<br>

Understand the different sinful reactions and make sense of the terminology<br>

3 stages of sinful reaction:
Phalonmukha: the fruit of sin (sinful action & suffering)
Kuta: the potential for sin (ignorance)
Bija: the seeds of sinful desires<br>

aprarabdha-phalam papam kutam bijam phalonmukham
kramenaiva praliyeta visnu-bhakti-ratatmanam
"There are different stages of dormant reactions to sinful activities to be observed in a sinful life. Sinful reactions may be just waiting to take effect [phalonmukha], reactions may be still further dormant [kuta], or the reactions may be in a seedlike state [bija]. In any case, all types of sinful reactions are vanquished one after another if a person engages in the devotional service of Lord Visnu
Madhya 15.169 purport<br>

Thus a fully surrendered, sincere devotee immediately receives relief from all kinds of sinful reactions. There are three stages of fructification for sinful activity. At one stage, one commits the sinful act, before that the seed of this act exists, and before that there is ignorance whereby one commits the sin. Suffering is involved in all three stages. However, Krsna is merciful to His devotee, and consequently He immediately nullifies all three stages -- the sin, the seed of sin and the ignorance that leads one to sin. The Padma Purana confirms this:
aprarabdha-phalam papam kutam bijam phalonmukham
kramenaiva praliyeta visnu-bhakti-ratatmanam

Madhya 17.95<br>

When does suffering stop?<br>

As explained in the twenty-eighth verse of the Seventh Chapter, a person who has completely ended the reactions of all sinful activities and who is fully engaged in pious activities, being freed from the duality of this material world, becomes engaged in devotional service to the Supreme Personality of Godhead, Krsna. In other words, those who are actually engaged in the devotional service of the Supreme Lord are already freed from all reactions
Bg 9.2 (pg 451)<br>

In fact, everyone is suffering the pangs of separation from Krsna. Because the conditioned soul imagines that he has no eternal relationship with Krsna, he is unable to ascertain that all his miseries are due to this separation. This is maya, or "that which is not." Actually, to think that misery arises from anything other than separation from Krsna is to be in illusion. So when a pure devotee sees living entities suffering within this world, he correctly feels that just as he is suffering because of separation from Krsna, all other living beings are also suffering from separation from Krsna. The difference is that a pure devotee correctly ascertains the cause of his heartbreak whereas the conditioned soul, bewildered by maya, is unable to understand his eternal relationship with Krsna and the unlimited pain arising from neglect of that relationship
SB 11.2.45<br>

How does surrendering help us?<br>

See Bg 7.28 (first paragraph)

“This elevation is possible in Krsna consciousness in the association of pure devotees, for in the association of great devotees one can be delivered from delusion.”
Bg 7.28<br>

See SB 3.25.23
AND
SB 3.25.24 (last para)<br>

We should note, however, that when a devotee falls into a miserable condition in this way, it is not due to past impious activities, known as karma-phala; the poverty of the devotee is a creation of the Personality of Godhead. Similarly, when a devotee becomes materially opulent, that is also not due to his pious activities. In either case, whether the devotee becomes poorer or richer, the arrangement is made by the Supreme Personality of Godhead. This arrangement is especially made by Krsna for His devotee just to make him completely dependent upon Him and to free him from all material obligations. He can then concentrate his energies, mind and body -- everything -- for the service of the Lord, and that is pure devotional service. .
K.B 88: The Deliverance of Lord Siva<br>

Another question may be raised: What is the difference between a devotee and a common man, since both are put into different kinds of happy and distressful conditions -- the devotee by the arrangement of the Personality of Godhead, and the common man as a result of his past deeds? How is the devotee any better than the ordinary karmi ? The answer is that the karmis and the devotees are not on the same level. In whatever condition of life the karmi may be, he continues in the cycle of birth and death because the seed of karma, or fruitive activity, is there, and it fructifies whenever there is an opportunity. By the law of karma a common man is perpetually entangled in repeated birth and death, whereas a devotee's distress and happiness, not being under the laws of karma, are part of a temporary arrangement by the Supreme Lord which does not entangle the devotee
KB 88: The Deliverance of Lord Siva<br>

When a devotee is put into a situation of distress, his devotional activities are accelerated. Therefore, to show special favor to a devotee, the Lord sometimes puts him into distress.
KB 88: The Deliverance of Lord Siva<br>

"A person who has developed detachment can give up the bondage of material society, friendship and love, and a person who undergoes great suffering gradually becomes, out of hopelessness, detached and indifferent to the material world. Thus, due to my great suffering, such detachment awoke in my heart; yet how could I have undergone such merciful suffering if I were actually unfortunate? Therefore, I am in fact fortunate and have received the mercy of the Lord. He must somehow or other be pleased with me."
[ SB 11.8.38 ]<br>