The act of God punishing the demons denotes
His way of purifying our negative qualities.  

“Is there a demon within me!?” It’s hard to believe it. One may think, “After all, I am neither a demon nor haunted by a ghost.” Yes! we are not ghostly, but godly. But its a fact that negative personality traits that are commonly found in demons are also sometimes found in common people. A responsible person diligently detects them in oneself and tries to eradicate them with determination and devotion. 

Demons Represents Our Frailties

Lord Krsna said in the Bhagavad Gita, “I descend to protect the righteous and punish the mischievous.” Protecting devotees is His primary concern, while punishing demons is secondary. However, His punishing is also a form of protection. After all, the Lord is the supreme father of all beings. He therefore lovingly protects His cultured children, and responsibly corrects His misguided children. His punishment or killing is His causeless mercy that transforms the lives of the demons and transfers them to higher levels of consciousness. 

In His various incarnations on this planet, the Lord killed and liberated several demons. These demons often represent various anarthas or unwanted personality traits in the practitioners of spiritual life. The devotees pray to the Lord to destroy those unwanted qualities in them just as He destroyed the demons. When one is purified of negative tendencies, one can easily make progress in spiritual life. 

In Vrndavana, Lord Krsna killed several demons including Putana, Sakatasura, Bakasura, Aghasura and so on. The Vaisnava acaryas explain that Putana represents a pseudo guru who misdirects innocent public towards sense gratification or liberation of both. Putana also represents the fickle mind that convinces a spiritual seeker to believe unfavourable things to spiritual life to be favourable. Similarly, Trnavarta represents pride in material scholarship. 

Hiranyakasipu, the personification of Material Desire.

Lord Nrsimha-deva was the divine half-man half-lion incarnation of the Supreme Lord. Nrsimha-deva killed the great demon Hiranyakasipu and protected his virtuous son Prahlada. Hiranya means “gold” and kasipu means “a soft bed”. Materialistic people immersed with the thoughts of sense enjoyment, always aspire for immense wealth to utilize it for exuberant bodily comforts. Their minds and hearts are filled with material desires. In other words Hiranyakasipu lives within them. Srila Prabhupada thus explains that Hiranyakasipu was the personification of material desire and was the perfect representative of materialistic life (SB 5.18.8 Purport). 

One whose mind is filled with selfish material desires and egoistic tendencies, often cause great disturbance to the devotees of the Supreme Lord, just as Hiranyakasipu tormented his own little son Prahlada. Hiranyakasipu threatened to kill Prahlada ruthlessly in various ways, until Lord Nrsimha-deva appeared to kill the demon. Similarly material desires torment spiritual seekers (sadhakas) in various ways trying to distract them from the path of pure bhakti. Therefore, any devotee aspiring to be free of material desires should sincerely seek the shelter of Lord Nrsimha-deva who compassionately destroys them, just as He killed Hiranyakasipu. Prahlada Maharaja prays to Lord Nrsimha as follows. 

“om namo bhagavate narasimhaya namas tejas-tejase avir-avirbhava vajra-nakha vajra-damstra karmasayan randhaya randhaya tamo grasa grasa om svaha; abhayam abhayam atmani bhuyistha om ksraum .”

“I offer my respectful obeisances unto Lord Nrsimhadeva, the source of all power. O my Lord who possess nails and teeth just like thunderbolts, kindly vanquish our demon-like desires for fruitive activity in this material world. Please appear in our hearts and drive away our ignorance so that by Your mercy we may become fearless in the struggle for existence in this material world.” (Bhagavatam 5.18.8)

When Material Desires are Absent… 

A pure devotee who has no material selfish desires in the heart, naturally desires the welfare of all living beings. Such devotees are completely free from material envy. Envy is a prominent anartha in the conditioned souls dwelling in this material world. Due to envy one develops the tendencies of unnecessary competition, comparison, complaints and criticism of others. One who is freed from the disease of envy becomes liberal in one’s social dealings and can think of others’ welfare. One who performs bhakti-yoga cleanses one’s mind of all envy. Therefore devotees pray to Lord Nrsimhadeva to sit in their hearts (bahir nrsimho hrdaye nrsimhah) and kill all bad propensities including envy. Unless one is freed from the disease of envy, one cannot enter the spiritual realm. 

So, Prahlada Maharaja fervently prays to Lord Nrsimha that envious people be purified by the practice of bhakti-yoga. 

svasty astu visvasya khalah prasidatam
dhyayantu bhutani sivam mitho dhiya
manas ca bhadram bhajatad adhoksaje
avesyatam no matir apy ahaituki

“May there be good fortune throughout the universe, and may all envious persons be pacified. May all living entities become calm by practicing bhakti-yoga, for by accepting devotional service they will think of each other’s welfare. Therefore let us all engage in the service of the supreme transcendence, Lord Sri Krsna, and always remain absorbed in thought of Him.” (Bhagavatam 5.18.9)

Glorifying Prahlada’s well-wishing nature, Srila Prabhupada writes, “Prahlada Maharaja is a typical Vaisnava. He prays not for himself but for all living entities—the gentle, the envious and the mischievous. He always thought of the welfare of mischievous persons like his father, Hiranyakasipu. Prahlada Maharaja did not ask for anything for himself; rather, he prayed for the Lord to excuse his demoniac father. This is the attitude of a Vaisnava, who always thinks of the welfare of the entire universe.” (Bhagavatam 5.18.9 Purport)

In this way, a sincere practitioner of bhakti has to diligently protect oneself from falling into the clutches of the anarthas of material desires and envy. One must learn the science of bhakti from pure devotees of Krishna who are the bona fide teachers or acharyas. If we are sincere in seeking shelter of Lord Nrsimha-deva, He will divert us from material desires and direct us towards spiritual activities.