Isaiah 61 promises the Lord's comfort to those who mourn, provision for those who grieve, and a heart that can praise rather than a spirit of despair. And then, at the end of verse 3, we are promised something a little bit unexpected. It says that we who have received all these wonderful comforts from God's hand will then be called "oaks of righteousness." We've done nothing but to receive God's good gifts, but now we are called righteous!
As I've made difficult decisions on my mother's behalf it has comforted me to know that when I couch every decision in prayer, it isn't my own "rightness" I'm depending upon, but the Lord's. This has helped me to be a little less fearful about making mistakes.