The word 'zeal' comes to mind, but 'zeal' infers total commitment to a cause, not to people. But the image is caught best, I think, by ' passion ', because passion is ordinarily seen as being directed toward some other person. God rewards this passionate love through spiritual gifts and blessings. It won't be noticed much at first. It will tend to just happen.
Prayers become more vibrant.
Counsel becomes more insightful. Words of insight, comfort and confrontation begin to come forth in a way that would in some contexts be seen as ' prophecy '. Because God is passionate. Really, that's the root of the passion I'm referring to. God loves us with a passion, and that is why the Covenant was made, the Son dies, the Spirit is sent, and the Kingdom comes.