Just some thoughts, for whatever they may be worth....
Guilt trips. IMHO, these only work, if (1) there's something to be guilty about, and (2) if there's nothing, yielding to the temptation to feel guilty. It's the same technique used by those showing small children with large sad eyes to solicite money for their particular cause. If, I know in my heart that I'm doing all I can to help the local needy, there's no reason why I should feel guility for not sending in x requested dollars in response to the commercial. Instead, ask if the thousands of dollars used for TV advertising came from those who are contributing to buy food, rather than air time?
"One thing properly" ..... I agree to do all that we do to be very best extent that we can for the Lord. But, in my humble opinion there are many thing we can do for the glory of God, both inside a physical building and in the body of Christ. Does "doing one thing properly" put a limit on God and what He's called us to do? Who decides whether it's better service to the Lord to be a greeter or help prepare meals for shut-ins? While an individual is equally prepared to do both without any sacrifice of other bibilcal responsibilities.
"Given things to do" ...... IMHO, we shouldn't be "given" anything to do, just as we shouldn't be told how much to put into the collection plate on Sunday morning. Doing things, whether 1 or 25, should come as freely from the heart as are the dollars in the offering plate. Instead of waiting for an "assignment" we should be at the front of the line of volunteers for whatever needs to be done. Then, we can decline, without guilt, to do anything that we aren't led to do by the Holy Spirit.
Another aspect.... Again, IMHO, there's more to church life than the music program and various worship/study opportunities during the week. There's the mundane things like replacing the toilet paper in the bathrooms and mopping the Fellowship Hall floor. Changing blown light bulbs, cleaning leaves from window wells, picking up broken animal crackers, and helping an elderly person to their vehicle.
Should I expect someone else to empty the nursery trashcan beside the changing table because I already have the job of keeping the thermostats adjusted? My answer is no. There's nothing that we should refuse to do, for the glory of God, simply because we have another job. Yes, there are times we should say no, with valid reasons, without any sense of guilt.
One question to ask ourselves when we are asked to do a second or even a third job is this. What am I giving up in order to do those jobs? Quality time from my family, a few extra hours of shut-eye or time in front of the TV? It doesn't matter what the person sitting beside me in the pew is or isn't doing with their time. Christ will judge them at the appropriate time, just like He will judge us. How will He judge you and I individually, with regards to service in/for the church, is all that matters, in the long run. Again, IMHO.
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