Acting upon loving desires results in joy while acting upon unloving desires results in pain
When we act upon our desires that are harmonious with love and truth then joy results: it’s an automatic result when we act upon desires harmonious with love and truth. So if we want to have joy or happiness in our life we must discover our desire and this proviso is that we want to make sure it is harmonious with love and truth, and then we want to act upon it. If we do all of that we’ll have joy. So you could say joy equals discovering your desire plus making sure it is harmonious with love and truth and then acting upon it. We add those three together; joy will result in our lives.