Bg 18.45

sve sve karmaṇy abhirataḥ
saṁsiddhiṁ labhate naraḥ
sva-karma-nirataḥ siddhiṁ
yathā vindati tac chṛṇu
Synonyms: 
sve sve — each his own; karmaṇi — work; abhirataḥ — following; saṁsiddhim — perfection; labhate — achieves; naraḥ — a man; sva-karma — in his own duty; nirataḥ — engaged; siddhim — perfection; yathā — as; vindati — attains; tat — that; śṛṇu — listen.
Translation: 
By following his qualities of work, every man can become perfect. Now please hear from Me how this can be done.