All the emotions we feel, be it love, excitement, sorrow, fear, happiness, peace, anger, jealousy or joy - can fall into two categories and there are Positive Emotions & Negative Emotions
Your feelings about something tell you very quickly whether you should or should not bring that thing into your life. When you understand the Law of Attraction, you'll learn to become aware of the way you feel and to pay attention to these feelings because they're your soul's guidance system, and will to help you hone in on things that are truly right for you.
Here's an example:
As a kid you may have played a game called 'hot or cold'. You would close your eyes and count to ten. A friend would hide something, say a toy, under a mattress or behind some books. When you're done counting and open your eyes, you now have to attempt to find the hidden toy.
Every time you move towards the location of the toy your friend would shout "WARM". If you moved away from the toy your friend would shout "COOLER". As you start to move towards the toy your friend would say "You're getting WARMER, WARMER..." And as you pinpoint the mattress and discover the toy, he'd shout "HOT - You found it!" And the Universe plays this game with you EVERY single day.
But rather than say HOT or COLD, the Universe guides you with feelings. Positive feelings mean you're moving towards something good for you. Negative feelings mean you're headed in the wrong direction.
You may wake up one morning feeling negative about your job. The repetitive work is boring you, you feel underappreciated, you just don't feel you're doing something you love. The negative feelings are a sign from the Universe that you need to change direction immediately. Changing direction does not mean quitting your job this instant - but it does mean you need to do something to fix your present situation.
You might feel the same way about your marriage, your career, your body, your home - the negative feelings are alarm bells going off. The Universe is saying "Warning , You're thinking thoughts that are not the reality you wish to face. Keep thinking them and you'll only increase the likelihood of these situations coming to you. You need to find a way to change your thought FAST!".
Your Emotions are therefore, a warning system from your Soul. Pay attention to them, so that you'll only attract into your reality things that are good for you.