Over the last year, I have had the singular opportunity to lay my hands upon my wife's head and give her blessings by the power of the priesthood. Every single time I do, I am awestruck by the power that allows me to speak for the Lord to my sweetheart. Anyone who has been inspired to speak by the Spirit can relate to this experience. Recently, however, the thought occurred to me that my priesthood service is an extension of Christ's atonement, and therefore must be done according to the Lord's will.
The Doctrine and Covenants reminds us that "the rights of the priesthood are inseparably connected with the powers of heaven, and that the powers of heaven cannot be controlled nor handled only upon the principles of righteousness" (D&C 121:36). In other words, anyone acting under priesthood authority, or trying to use the priesthood that has been conferred upon them, will only have priesthood power if they are "seek[ing] not [their] own," but are seeking the will of God.
Sometimes, when I give my wife a blessing, I worry that the Lord won't say what she wants to hear. When I let these concerns crowd my mind, I can sometimes think of good things to say to her, but they come without the power that accompanies a normal blessing. If, on the other hand, I clear my mind and allow the Lord to give me the words to say, I feel the blessing come much more easily, and the Spirit is stronger. I'm grateful that the Lord, in His mercy, is able to provide a way to speak to His children without any earthly being having to know the right words to say. And even if I stumble with the wording of a blessing, the Spirit will always speak to my wife and help her understand what I was trying to express.
Anyway, the bottom line that I wanted to share is that as long as we act in accordance with the Lord's will, we will have power to do whatever it is He asks. If we try to do our own will, we'll be left to our own power.