In the case of persons like Duryodhana, the struggle is still worse. He knew what Dharma was and what constituted Adhrma.
Janami Dharmam na cha me pravrittihi Janamyadharmam na cha me nivruttihi
Kenapi devena hridi sthitena yatha niyuktosmi tatha karomi
"I know Dharma but I am not inclined to follow it; I know Adharma, but I do not refrain from it. I do as I am goaded by a certain power residing in my heart."
Thus, the struggle is greater.
Ekanthji further cautions us about the saj-dhaj kar aave aakarshan - the temptations that come in front of us. Moving away from it requires a resolute will. But it takes time to form and so gradually and through understanding, constant introspecting, we need to move onward. Eknathji says :
Again a person knows his duties well, he struggles strenuously for the fulfillment of his duties, but the temptations intervene. The tongue allures a person to eat something which has been prohibited to him for his good. Thus, the organs both of sense and activity do not co-operate. The Gita has aptly described the situation in the verse:
Atha kena prayuktoyam papam charati purusha
Anichchannapi Varshneya baladiva niyojitah BG -III.36
"Oh son of Vrishnis, propelled by whom does the man perform a sin, even though reluctant, but commanded, as if, by force".