Bg 18.45

sve sve karmany abhiratah
samsiddhim labhate narah
sva-karma-niratah siddhim
yatha vindati tac chrnu

Word for word: 
sve sve — each his own; karmani — work; abhiratah — following; samsiddhim — perfection; labhate — achieves; narah — a man; sva-karma — in his own duty; niratah — engaged; siddhim — perfection; yatha — as; vindati — attains; tat — that; srnu — listen.

Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
By following his qualities of work, every man can become perfect. Now please hear from Me how this can be done.