Oh I know there are many ways feelings can deceive and can't be our guide, but I do think you couldn't live the Christian life at all without having changed feelings.

I don't think that quote, "For this is the love of God, that we keep His commandments" implies that we can just grit our teeth and obey even if we have no desire whatever to obey -- even if we could at first we couldn't do it consistently for the rest of our lives -- but that some degree of the feeling of love of God will work itself out in the desire to obey that leads to keeping His commandments. In fact I think we come to love His commandments and we couldn't obey them if we didn't. "Oh how I love thy law, it is my meditation all the day."

We can be so full of hurt and anger at being mistreated that blessing our enemies, or forgiving them is an emotional impossibility. SOMETHING has to change in the feelings away from hatred and toward love, however slightly, even a less severe degree of hatred, in order for us to obey in this case. It's like when Corrie Ten Boom was faced with the newly born-again Nazi who had abused her sister when they were in the concentration camp, and had to pray the Lord would give her the ability to shake his hand. Some people have more ability to act against their feelings than others do. I have to actually see the situation differently and feel at least a little differently about it before I can obey. I have to see that I'm no better than my enemies, for instance, or be reminded that the Lord is my reward, and then my feelings change enough to do good to them. If you can obey effectively in spite of deep anger at someone, I admire that ability, but I don't have it.

Have you read Jonathan Edwards' The Religious Affections? He covers the whole range of the subject including all the errors of trusting in feelings instead of acting on simple faith.

(I guess maybe I'm saying that faith changes our feelings. I don't want to ground our faith in feelings, though.)