Rabbi Sholom Dovber Schneerson (the 5th Lubavitcher Rebbe) once instructed his son (who later became the 6th Rebbe) to help a particular person during one of his travels. I don’t know the details of who the person was, or what kind of assistance was needed.
Upon his return, Rabbi Yosef Y. Schneerson told his father, “I did exactly as you instructed me, and I did the favor for the person even better than you requested.”
“You’ve got it all wrong,” Rabbi Sholom Dovber told his son. “You did a favor for yourself, not him. G-d Himself did the favor for the person by arranging that a messenger should fulfill His desire to help this person. The favor that you did was actually to yourself.”
If G-d wants to help someone, He will find a way. We are granted free will, and the only question is if we grab the opportunities presented to us to help others. When we help another, we are actually (just) helping ourselves.
As our sages teach (Vayikra Rabba 34:8), “More than the wealthy person does for the poor person, the poor person does for the wealthy person.”
I find this to be such a humbling view of life: How fortunate I am for every opportunity I have to help another person!