He clarified the Juche-based revolutionary line in "The Path of the Korean Revolution", a report made by him at the historic Kalun Meeting in Juche 19 (1930), and indicated the tasks and ways for solving the problems arising in successfully carrying out the Korean revolution in an independent and creative way.

In the works published in each period and at each stage of the anti-Japanese revolutionary struggle, including "The Tasks of Communists in the Strengthening and Development of the Anti-Japanese National-Liberation Struggle" and "Let Us Break the Present Deadlock and Lead a Continuous Advance of the Revolution", he consistently stressed that the Korean communists should firmly maintain the independent stand.

He also authored lots of works that set forth the policies for the expansion and development of the anti-Japanese revolutionary struggle, including the position of the armed struggle in the national liberation struggle in colonies, the strategy and tactics of the armed struggle with guerrilla warfare as their keynote, the establishment of guerrilla bases, and the laying of mass foundations.

In the 1940s he published such works as "Let Us Accomplish the Cause of National Liberation with Full Confidence in Victory" and "We Should Carry Out the Korean Revolution by Our Own Efforts" to cope with the new situation in which the Japanese imperialists' moves for continental aggression got more vicious and the Soviet-Japan Neutrality Pact was concluded. He instilled into the people and members of the Korean People's Revolutionary Army (KPRA) the firm faith that they can carry out the Korean revolution with their own efforts, and encouraged all the small units and groups of the KPRA and the revolutionary organizations in the homeland to wage a more courageous struggle for national liberation with their own efforts.

In his historic speech made at the Tumubong Meeting in 1943 "Let Us Achieve the Cause of National Liberation by the Efforts of Our Nation by Implementing the Three-point Line of National Liberation", he scientifically analyzed the situation at home and abroad and indicated the three lines for national liberation and the concrete tasks and ways for implementing them.

The Korean people successfully accomplished the historic cause of national liberation under the outstanding leadership of Kim Il Sung who firmly maintained the independent stand and led the nationwide struggle for defeating the Japanese imperialists, with firm reliance on the internal revolutionary forces in the period of the anti-Japanese revolutionary struggle.