You could do it the old fashioned way. This is the way my Grandmother did it. She sat in the very front row of the church (with all seven kids). Every time one of them needed her help in the dicipline department, she took them out and helped them. ~ Help in the form of a spanking. ~ If they needed her help several times in one service, they got it. If more than one kid needed help, well, lets just say, she made time for all of her children. (She was a good mama, and still is. I hope I can be as good a mama as my Grandma!) And we know it worked for her, because 50 plus years later they are all sitting in church, nice and quiet (except for the ones who are pastors). By the way, my parents used this method as well and it worked on us too! ;) This method has been tried and tested and I can tell you that it works!!
My Grandma and Grandpa.
I'm so thankful for Godly grandparents!!
You can do it the "new-fashioned" way. (This is the way I did it - the only difference between this way and the old way is that the "helping" is done at home.) I trained my children to sit quietly at home. When each kid was about 18 months old, I sat them down and turned on some music. No TV. No pen and paper. No sippy-cup. No toys. (Because I don't allow these things in church.)
They had to sit quietly for 10 minuets at a time. We called it our "quiet time". We did it once or twice every day. Most days just once...unless I needed a break, then a second "quiet time" was scheduled. Schedules around our house change quickly and, for a while "quiet times" were imminent.
ANYWAY, they would sit quietly for about ten minuets. (The best time for me to do this was right after nap time, when they are still a little bit sleepy.) The first time I would help them to understand what was expected of them. I would sit beside them - not beneath them. They would watch me and do what I did. If they got up or made noise, I would warn them once. The second time I would swat them once with a tiny switch on their bottom. Most of them did very well the first time and only got about 2 swats. One didn't get any, and then one of them needed a little more "encouragement", but after that first quiet time, she got the idea and did very well also. After the child had learned to sit quietly and not get up - even when/if I left the room - I would use this time to wash dishes, or switch a load of laundry.
When they could sit quietly for ten minuets, we went a little longer. It only took us about 3 weeks to stretch our quiet times from 10 minuets to 45 minuets (which is about the normal length of a sermon). I figured if they could sit quietly at home for 45 minuets, they could do it at church. And they did! I've never had to take my kids out of a service. At least not for misbehaving.
Quiet times have changed for us now. Today, when I say "it's quiet time", the kids get a book and rest in their beds while I read my Bible. The 2 little guys will usually fall asleep (that's so nice!) and sometimes the older ones will too. I've noticed a couple of times that the older ones will get their Bibles when it's quiet time. I've never told them what to read, but I am hoping that they will develop a habit of reading their Bibles every day. After all, Everybody Needs a Quiet Time!