Answer
Krishna consciousness does not require everyone to abandon their occupation.
A businessman remains a Krishna conscious businessman, a brāhmaṇa remains a Krishna conscious brāhmaṇa, and each person continues performing his prescribed duties while adding Krishna consciousness to them.
However, the modern world is a highly complex ugra (intensely materialistic) civilization, and merely giving theoretical answers is insufficient.
The holy name possesses the power to elevate consciousness far beyond material designations. Social systems such as varṇāśrama and occupational duties are material arrangements. Compared to the transformative power of chanting the Hare Krishna mahā-mantra, these external arrangements are secondary.
Even within an industrialized and materialistic civilization, people can become spiritually happy by sincerely chanting the holy name. Although it may be challenging, it is certainly possible.
Varṇāśrama and properly performed occupational duties support spiritual life, but by themselves they do not elevate one to pure devotion. One may even be a highly qualified brāhmaṇa and still remain materially conditioned.
The distinguishing feature of Krishna consciousness is that sincere chanting of the holy name raises one's consciousness above material conditioning. As consciousness rises, the binding influence of material civilization gradually weakens.
This is exactly what devotees practice today. They continue their professions without necessarily abandoning them. Srila Prabhupāda advised devotees to "make the best use of a bad bargain."
The essential requirement is to reserve sufficient time every day for chanting, hearing, and devotional practices.
One of Maya's greatest strategies is to gradually consume a person's time.
For example, someone may begin with an eight-hour workday. Promotions bring increased salary but also increased responsibilities and longer working hours. Eventually, a person may work ten or eleven hours a day, leaving little or no time for spiritual practice.
Therefore, devotees must consciously protect three to four hours each day—especially during the early morning and evening—for chanting, studying, and devotional service.
If this spiritual foundation is maintained, one's occupational duties will not obstruct spiritual advancement.
Lord Caitanya Mahāprabhu taught that wherever one is situated, one should simply add the chanting of the Hare Krishna mahā-mantra to one's life. The holy name elevates consciousness because it is non-different from Krishna Himself.
The immense spiritual power of the holy name far exceeds the limited effects of merely following or failing to follow material social systems. Sincere chanting covers innumerable deficiencies and steadily elevates the soul toward pure Krishna consciousness.