How do you know your doing God's work?

That was a question I asked myself all the time for all different things. How do I know if what I am doing is what God wants me to do. There are many different ways and a biblical checklist on what to look for... is it in line with Godly principals, etc. The best advice I ever got, though, was from an older lady at our previous church. She said that you can tell your doing God's will when you can feel him holding your hand while the devil is kicking you in the behind! That being said, I certainly feel as if I'm being kicked lately. The last time the children came to live with us, 2 days after, Kamryn nearly drowned in a pool, then we were sued by their ex-stepfather for custody of the kids (and had to spend 5000 we didn't have on a lawyer), followed by behavior issues with TJ, losing our house, etc. Through it all I felt God's hand guiding us and caring for us and I never once regretted having the kids live with us- trying as it may have been. Especially when I considered the alternative. Now that they're here again I feel as if we've given Satan one more black eye and for that he's giving us a swift kick in the behind. Things are getting tougher and tougher with all the rain and Greg's hours being cut back. I think and begin to doubt, "are we doing the right thing?". Then little things begin to happen. Stacy tells me how much she loves going to church with us, Siarah thanks me for a home cooked meal and family dinner time at the table, and TJ comes to me and tells me how much he loves me and I feel God's hand in mine saying "the one who was born of God keeps him safe, and the evil one cannot harm him" and I am reminded that is my job. To keep the children safe and that no matter what, the kids (ours included) may not have everything they ever wanted but they will know what a Godly, loving family looks and feels like and will understand the comfort and peace of a stable environment. God will take care of the rest.