I would pose that "service to others" if reflected upon, is exactly ego. You can feel good being of service to others, and you can feel diminished by not being of service to others. When you lose the good feeling, you want to do more, to reobtain that good feeling.

"I am one who strives to live in service to others" (I am parahrasing) but if this is true, it is more clearly ego a.k.a. identification with form.