“You can tell if you are in God’s will by the ‘indicator of peace’—if you are in God’s will you will have peace, if you’re not, your peace will lift.”
If this were true, Jesus would have been out of God’s will in the Garden of Gethsemane and in his suffering on the cross. His was not a picture of peace (the kind referred to in this saying) but of agony, even questioning, though he gained what might be called resolve.
Using the peace as indicator formula has enabled Christians to come up with some outrageous self-permissions such as “It’s okay if I have a room mate of the opposite sex because we aren’t doing anything,”(yet) or “I have peace about leaving my husband because God wants me to be happy.” Remember the adage from the 1960’s? “If it feels good, do it.” The human mind can manufacture all sorts of things to justify what it wants—or lie about it.
No, the best indicator of God’s will is what the Holy Spirit has already spoken in the Bible (especially the New Covenant). You may think that it doesn’t cover everything for contemporary living—dig a little deeper, make sure you’re asking the right questions (the most basic ones)—you might be surprised how much is there.