Bhagavad Gita: Understanding One Shloka at a time. (Chp. 4, Verse 7) — HBR Patel
यदा यदा हि धर्मस्य ग्लानिर्भवति भारत |
अभ्युत्थानमधर्मस्य तदात्मानं सृजाम्यहम् || 7||
Whenever and wherever there is a decline in righteousness, and a predominance of the unrighteousness prevails, at that time I manifest myself personally, O descendant of Bharata.
If Bhagwan Shri Krishna manifested in the past to instruct Vivasan on the principles of the Karmayoga, then there arises a question that how many and where & when did all these manifestations take place? What is the reason behind these manifestations?
To answer this pre-born question, Bhagwan Shri Krishna explains to Arjuna the reason behind the Avatar(the divine manifestation of Bhagwan on this mortal world). Whenever there is a decline in Dharma (righteousness) and wherever there is a predominance of Adharma (unrighteousness), Bhagwan manifests Himself personally to restore the balance.
Sometimes, the real meaning is lost in translation. When we look at a given term through emotionless language, we get only the word that it means and the true meaning and emotion attached to that is lost in translation.
The same is with the word Dharma which translates to Righteousness but many fragments of the word Dharma is not explained by its translation. The code of conduct is included in the Dharma but here Dharma also means the science of the individual consciousness attaining communion with the ultimate consciousness by the means of loving devotion. When the bhakti-yoga takes a back seat in our daily conduct. When the people in power oppose the path of Bhakti-yoga, Bhagwan manifests on this mortal world in the form of an Avatar to restore balance.
The lifetime of the Avatar is defined by the objectives he wishes to accomplish with that Avatar. Bhagwan manifested into Narasimha for only a short time as that avatar was to protect Prahlad and destroy the evil Hiranyakashipu. Sometimes, the objective takes a longer period to complete and thus, Avatar stays for a longer period on this earth like Bhagwan Shri Ram.
Thus, to restore the Dharma and uproot the evil Adharma, Bhagwan manifests on this mortal world.