Volunteering service to another by means of fraternal organizations, service clubs, community groups, church organizations or just by doing it of your own free will of course carries the side result of feeling good about yourself and I can see where some would do it out of the NEED for self-interest. I.e. the need to do something to get that pat on the back or chance to say “see what I did, now tell me what a good person I am.” This by no means a valid reason for doing so. Performing Service for your fellow man should have been part of your upbringing as taught by your parents, mentors, teachers and clergy. As for Frank and Jake’s comments, duty to respond to the aid of others should have been included in your rearing as well.
I admit that I do get satisfaction out of the many things I do both as a volunteer and as a passerby in life that takes the time to help others, but by no means is this the reason I do it. My satisfaction comes from knowing that my one step or action when multiplied by all the people that are doing the same, help make this a better place to live in and raise my kids.
The actions I perform are the actions I saw my Father perform, the things that made a real man and a real father. I do my best to emulate his actions to try to live as a good man and a good father for my children. I have been brought up and have joined an organization where part of our obligations includes this duty to our fellow man, to the length of my abilities and to the point of no injury to myself. By helping others, I hope to pass these values onto my daughters so that there are three more people helping others.
As for not joining a large group out of fear that they are corrupt, treat the volunteers wrongly or not joining and those worried about duplication or services. There are many people that, out of lack of knowledge, fear of asking or just too much pride to ask for help, need people that are just willing to strike out on their own and offer help.
By helping your fellow man, there is no reason you should not be able to sit back at the end of the day and feel good about the way you choose to live your life.