So the Lord sometimes appears as... Whenever the Lord takes the incarnation, He appears to be like ordinary human being. So in this incarnation, Nara-nārāyaṇa, They undertook severe penances to teach us. So what was the purpose of such severe penance? For sense controlling. The modern civilization is to give freedom to sense satisfaction, because they cannot control. Just like you are riding on a horse, but the horse is not under your control, then you say, "Let it go to hell, never mind." This is the position. Because they cannot control the senses, they have taken this philosophy that liberating sense gratification is the ultimate goal of life. And the result is that they are going to hell.
Adānta-gobhir viśatāṁ tamisraṁ punaḥ punaś carvita-carvaṇānām [SB 7.5.30]. The problem is they cannot control the senses. Therefore their philosophical idea is that sense gratification is the ultimate goal of life. They are thinking, which will never be successful, that by advancement of material comforts they will be happy. Therefore the śāstra says impossible or very difficult or by a kind of hope which will never to be fulfilled. It was never successful in the past, it is not successful in the present, therefore in the future also it will never be successful. But they have taken up this philosophy of sense gratification materially.
Prabhupada's lecture - Śrīmad-Bhāgavatam 1.3.9 Los Angeles, September 15, 1972