The Rebbe's encouragement for those whose outreach meets opposition, setbacks or no visible results:
No effort is ever wasted. Every sincere effort to inspire another Jew leaves its mark, even when it isn't visible (IK 2168, 3629, 5129, 5938); words of Chassidus always have an effect, even if unnoticed at first (IK 2004). Efforts to influence others in mitzvos are never wasted (IK 3392), and educators should never despair over an apparent lack of results (IK 3809). Keep reaching out even when results seem hidden (IK 1129), and never give up on anyone, however resistant (IK 072, 152).
Discouragement comes from the yetzer hara. Discouraging thoughts about one's success in holy work are tactics of the yetzer hara; dismiss them and add effort (IK 3407, 4637, 4701, 4727, 6148). A setback calls for renewed effort and creative new approaches (IK 5552, 7947). Mistakes are lessons, not reasons to stop (IK 6136). All beginnings are hard, but nothing stands in the way of true will (IK 3596, 3605, 4026); even a small opening or a small gathering brings great blessing (IK 2631, 7958, 8063). One person alone can accomplish much (IK 5646), and feeling alone should not stop one's efforts (IK 3144).
Facing opposition. Opposition to spreading Chassidus is nothing new; it existed even for our greatest leaders, and it should only make us redouble our efforts (IK 2401, 2437, 5127, 5395, 5728). Opposition is a test of commitment, and perseverance inspires others (IK 2182, 7174). It often comes from misunderstanding, so speak sincerely and respectfully, from the heart (IK 3184, 5926). Oppose the issue, not the person, and treat people respectfully even while standing firm (IK 2103). Even those who think they oppose Chassidus have an inner point connected to it (IK 1989). In the end, we will be victorious (IK 2920, 8166).
See also: Jewish outreach – How to reach others; Emotional well-being – Self-confidence and feelings of failure.