How do you know if you have the Holy Spirit?

Here is a list by Elder John H. Groberg, April 1986 Ensign.

http://www.lds.org/ensign/1986/04/investing-for-eternity?lang=eng

When You Have the Spirit  When You Do Not Have the Spirit  1. You generally feel happy and calm. You may feel unhappy, depressed, confused, frustrated most of the time. 2. You feel full of light. You may feel heavy, full of darkness. 3. Your mind is clear. Your mind may be muddled. 4. You feel love for the Lord and others. You may feel empty, hollow, cold inside. 5. You feel generous. You may feel selfish, possessive, self-centered. 6. Nobody can offend you. You may be offended easily. 7. You are very forgiving and kind. You may usually be on the defensive. 8. You feel confident in what you do. You may become discouraged easily. 9. You don’t mind others seeing what you are doing. You may become secretive, evasive. 10. You want to be with those who love you—especially family members. You may want to be alone most of the time. You avoid others—especially family members. 11. You are glad when others succeed. You may be envious almost constantly of what others do and what they have. 12. You want to help others be happy, even those opposed to you. You may want to get even and show others up. 13. You willingly perform Church work. You may feel hesitant, unworthy, and unwilling to perform Church ordinances. 14. You feel like praying and reading the scriptures. You may not want to pray or read scriptures. 15. You wish you could keep all the Lord’s commandments. You may find the commandments of God and rules of the family bothersome, restricting, or senseless. 16. You usually control your appetites and emotions. You are calm and control your speech; you feel no anger. You may be a slave to your appetites. You give way to strong anger and outspokenness. 17. You generally feel a deep desire to help others—usually in a way no one else will know about. When you help others, your main desire may be to have your actions noticed. 18. You speak and think good about others. You are critical of others, especially family members and those in authority. 19. You feel sorrow when others have problems and sincerely desire to help them. You may often question others’ motives and secretly delight in others’ problems. 20. You realize that your thoughts and your actions are open to God. You may feel that what you do and think is only your business and no one else knows or cares.