​MN 45 Culadhammasamadana Sutta: The Shorter Discourse on Ways of Undertaking Things 

Thus have i heard. 

On one occasion the Blessed One was living at Savatthi in Jeta's Grove, Anathapindika's Park. There he addressed the bhikkhus thus: "Bhikkhus, there are four ways of undertaking things. What are the four?
1. There is a way of undertaking things that is pleasant now and ripens in the future as pain.
2. There is a way of undertaking things that is painful now and ripens in the future as pain.
3. There is a way of undertaking things that is painful now and ripens in the future as pleasure.
4. There is a way of undertaking things that is pleasant now and ripens in the future as pleasure.

"What, bhikkhus, is the way of undertaking things that is pleasant now and ripens in the future as pain? Bhikkhus, there are certain recluses and brahmins whose doctrine and view is this: 'There is no harm in sensual pleasures.' They indulge in pleasures and divert themselves with women wanderers who wear their hair bound in a topknot. They say thus: 'Now what future danger concerning sensual pleasures do those recluses and brahmins foresee that they have spoken of the relinquishment of sensual pleasures and describe the full comprehension of sensual pleasures? It's pleasant to a woman wanderer's soft, tender, downy arm.' Thus they indulge in sensual pleasures, and having done so, on the dissolution of the body, after death, they reappear in a state of deprivation, in an unhappy destination, in perdition, even in hell. There they feel painful, racking, piercing feelings. They say thus: 'This is the future fear those good recluses and brahmins saw in sensual pleasures when they spoke of abandoning sensual pleasures and described the full understanding of sensual pleasures. For it is owing to sensual pleasures,that we are now feeling painful, racking, piercing feelings.'   

"Bhikkhus, suppose that in the last month of the hot season a maluva-creeper pod burst open and a maluva-creeper seed fell at the foot of a sala tree. Then a deity living in that tree became fearful and frightened; but the deity's friends and companions, kinsmen and relatives - garden deities, park deities tree deities, and deities inhabiting medicinal herbs, grass, and forest-monarch trees - gathered together and reassured that deity thus: 'Have no fear, sir, have no fear. Perhaps a peacock will swallow the maluva-creeper seed or a wild animal will eat it or a forest fire will burn it or woodsmen will carry it off or white ants will devour it or it may not even be fertile.' But no peacock swallowed that seed, no wild animal ate it, no forest fire burned it, no woodsmen carried it off, no white ants devoured it, and it was in fact fertile. Then, being moistened by rain from a rain-bearing cloud, the seed in due course sprouted and the maluva creeper's tender soft downy tendril wound itself around that sala tree. Then the deity living in the sala tree thought: 'What future fear did my friends and companions, ... relatives.. .see in that maluva-creeper seed when they gathered together and reassured me as they did? Pleasant is the touch of this maluva creeper's tender soft downy tendril!' Then the creeper enfolded the sala tree, made a canopy over it, draped a curtain all around it, and split the main branches of the tree. The deity who lived in the tree then realized: 'This is the future fear they saw in that maluva-creeper seed. Because of that maluva-creeper seed I am now feeling painful, backing, piercing feelings.'

"So too, bhikkhus, there are certain recluses and brahmins whose doctrine and view is this: "There is no harm in sensual pleasures.'...They say thus: 'This is the future fear those good recluses and brahmins saw in sensual pleasures...that we are now feeling painful, racking, piercing feelings.' This is called the way of undertaking things that is pleasant now and ripens in the future as pain.

"And what, bhikkhus, is the way of undertaking things that is painful now and ripens in the future as pain? Here, bhikkhus, someone goes naked, rejecting conventions, licking his hands, not coming when asked, not stopping when asked...(as Sutta 12) ..He dwells pursuing the practice of bathing in water three times daily including the evening. Thus in a variety of ways he dwells pursuing the practice of tormenting and mortifying the body. On the dissolution of the body, after death, he reappears in a state of deprivation, in an unhappy destination, even in hell. This is called the way of undertaking things that is painful now and ripens in the future as pain.

"And what, bhikkhus, is the way of undertaking things that is painful now and ripens in the future as pleasure? Here, bhikkhus, someone by nature has strong lust, and he constantly experiences pain and grief born of lust; by nature he has strong hate, and he constantly experiences pain and grief born of hate; by nature he has strong delusion, and he constantly experiences pain and grief born of delusion. Yet in pain and grief, weeping with tearful face, he leads the perfect and pure holy life. On the dissolution of the body, after death, he reappears in a happy destination, even in the heavenly world. This is called the way of undertaking things that is painful now and ripens in the future as pleasure. "

​"And what, bhikkhus, is the way of undertaking things that is pleasant now and ripens in the future as pleasure? Here, bhikkhus, someone by nature does not have strong lust, and he does not constantly experience pain and grief born of lust; by nature he does not have strong hate, and he does not constantly experience pain and grief born of hate; by nature he does not have strong delusion and he does not constantly experience pain and grief born of delusion. Quite secluded from sensual pleasures, secluded from unwholesome states, he enters upon and abides in the first jhana...With the stilling of applied and sustained thought, he enters upon and abides in the second jhana. With the fading away as well of rapture.. .he enters upon and abides in the third jhana...With the abandoning of pleasure and pain...he enters upon and abides in the fourth jhana...On the dissolution of the body, after death, he reappears in a happy destination, even in the heavenly world. This is called the way bf undertaking things that is pleasant now and ripens in the 'future as pleasure. These, bhikkhus, are the four ways of undertaking things."
 
That is what the Blessed One said. The bhikkhus were satisfied : and delighted in the Blessed One's words. 

In summary, the Buddha explained the four ways of undertaking things, distinguished according to whether they are painful or pleasant now and whether they ripen in pain or pleasure in the future. Indulging in sensual pleasures and practicing self mortification will result in pain and suffering, rebirth in unhappy destination. Whereas if one abandons lust, hate and delusion; going into deep meditative states achieving jhana then one will experience pleasure and will be rebirth in happy destinations. 

​By WHH

References: 
1. www.accesstoinsight.org
2. https://suttacentral.net/
3. The middle length discourses of the Buddha (Bhikkhu Bodhi)