Reason must always keep a check on emotions, making sure they are sending correct signals, and correcting their recommendations when they are not. But, without emotions, reason would be dead. For reason is the slave of emotion.
Reason is not a motivator. Reason is a tool. But for that tool to be applied, you must be motivated to apply it, and what you apply it to depends on your goals, which are in turn the result of motives, and motives are the product of desires, and desires are the outcome of emotions.
For example, if you love someone, that love will generate certain desires with regard to that person, such as a desire that they be happy. Then you should apply reason to work out how to satisfy that desire. Thus, reason is the servant of the emotion.
But emotions can be in error. So if you love someone because of false beliefs, reason can correct those beliefs, causing you to stop loving them. Or if you love a person for the wrong reasons, reason can detect this and produce the conclusion that this love is wrong.
Reason is directed. It is employed, for purposes not its own, because reason alone cannot have a purpose. A purpose must be given to it. It must be assigned a goal.
Emotions provide the impulses and desires for certain ends. They are also a form of information, vital for deciding what to do, every moment of every day. So we need to pay attention to our emotions and take them seriously: make sure they have correct information to work on and are working properly.
Carrier, R. (2005). Sense and Goodness without God: A defense of Metaphysical Naturalism. USA: Author House.