Different people are called to different things... some are called to the masses, and some are called to just one or two.
I know I'm designed for small, intimate groups. I've written about this before--I spent several years of my singledom writing to prison inmates. During that time, I sent letters out to probably 300 people over a time span of about 5 years. Some never wrote back, some wrote for a few months, some I knew right away I wasn't called to.
Out of those 300, I was called to one on a long-term basis, and we still keep in touch. I consider him to be one of my closest friends. It was every bit worth the effort. I've had problems with depression all my life... I showed up at some of our visits with cuts going around my arms and ankles. This person talked with me, prayed with and for me, and didn't flinch when I got angry or defensive. Because of what he'd been through, I eventually came to respect what he was trying to tell me and I can say that it's because of his prayers and influences that I don't cut anymore--even though I'd been through many, many years of counseling, antidepressants, church classes, conferences, etc. I was raised in church all my life, but when I tried to tell my pastor's wife about it, she patted me on the shoulder and said, "Oh, my (child's) friend does that too," and sent me on my way as if I hadn't said a word. This is another reason why this inmate made such a difference in my life. He was willing to confront me head-on, even though I told him I hated him at the time and that he could go to hell, for all I cared. That's how much anger I had stuffed away inside. But he kept praying and he didn't give up or ignore my anger.
God didn't choose someone in the everyday church or the field of psychology to make that key difference. He choose this particular inmate. I am fully convinced, not just from being told, but from living, breathing proof in my own life that God can use anyone in any circumstance if they are willing. I often wonder if I would have still been healed had I not met this person... and how many more people out there have a miracle waiting for them, but it's hidden within the heart of a person they'd probably never talk to.
And I hope that someday, God will use me to make that kind of impact on other people's lives as well, even if it's just one person at a time.