One can become perfect by doing all the duties of his respective varna for the “Lord’s pleasure”
By worship of the Lord, who is the source of all beings and who is all pervading
Srila Prabhupada elaborates in this purport on how one’s work—although within the modes of material nature—can be practically turned into bhakti through niskama-karma-yoga
aSupreme Lord is the beginning of all living entities — This is supported by the following references:
Bg. 15.7 – Living entities as fragmental parts and parcels
Vedanta-sutra – “janmady asya yatah…”
Bg. Chapter 7 – Lord is all pervading by His external and internal energies
bResult of knowing the Lord as the source — This leads to “Worship of him”
Worship Supreme Lord with His energies
How Vaishnavas worship – Worship Lord especially with His internal energy
But what about external energy?
His external energy is a perverted reflection of internal energy
The external energy is a background, but the Supreme Lord by the expansion as Paramatma is situated everywhere, in all the demigods, human beings, animals etc.
Therefore recommendation given: Perform your duty to render service unto Him – Senses to be engaged in service of Hrsikesa, the master of the senses
cReciprocation of the Lord (Ref. Bg. 12.7) — Supreme Lord Himself takes charge of delivering such a devotee
Whatever occupation one may be engaged, if he serves the Lord, he will achieve the highest perfection