Christianity is an experience. But how do I know if I’m having the kind of experience God intended? Jonathan Edwards listed the characteristics of true spiritual experiences in his book Religious Affections (paraphrased here by Nicholas Needham):
1. True spiritual experiences arise from spiritual, supernatural, & divine influences on the heart. Christians are spiritual because they are born of Godʼs Spirit and because the Spirit lives within them. Things are spiritual because of their relationship to the Holy Spirit, see 1 Corinthians 2:13.
2. The object of spiritual experience is the loveliness of spiritual things, not our self interest. People whose love for God is based on God’s usefulness to them are beginning at the wrong end. They are regarding God only from the viewpoint of their own self-interest. They are failing to appreciate the infinite glory of God’s nature, which is the source of all goodness and all loveliness. Anything is lovely to a selfish person… if it advances his or her self-interest.
3. Spiritual experiences are based on the moral excellence of spiritual things. What do I mean by the moral excellence of spiritual things? I am not referring to the mere outward performance of duties or the unspiritually motivated virtues an unbeliever can have, such as honesty, justice, generosity, etc. What I mean is the sort of excellence that belongs to God’s moral character. I am talking about the holiness of God. God’s holiness is the sum total of his moral perfections, his righteousness, his truth, and his goodness. I am talking about the qualities of God’s character. What a true Christian loves about spiritual things is their holiness. He or she loves God for the beauty of God’s holiness.
4. Spiritual emotions arise out of spiritual understanding. Spiritually emotions are not heat without light. They arise out of spiritual illumination. The true Christian feels, because he sees and understands more of spiritual things than he did before. Doctrinal knowledge involves the intellect alone, but spiritual knowledge is a sense of the heart by which we see the beauty of holiness in Christian doctrines. Spiritual knowledge always involves the intellect in the heart together.
5. Spiritual emotions bring a conviction of the reality of divine things. The true Christian has a solid conviction of the truth of the gospel. He no longer hesitates between two opinions. The gospel becomes settled and indisputable in his mind.
6. Spiritual experiences always exist alongside spiritual humiliation. Spiritual humiliation is the sense a Christian has of how insufficient and detestable he is, which leads him to abase himself and exalt God alone. Spiritual humiliation is the essence of true religion. Those who lack it are not genuine Christians, no matter how wonderful their experiences may be. Scripture is full of its testimony to the necessity of this humiliation. See Psalm 34 verse 18; Psalm 51 verse 17; Isaiah 66 verse 1 and 2; Matthew 5 verse 3; and the parable of the Pharisee and the tax collector in Luke 18 verse 9 through 14.
7. Spiritual experiences always exist alongside a change of nature. Spiritual sight has a transforming effect. See 2nd Corinthians 3:18. This transforming power comes only from God, from the Spirit of the Lord. Scripture describes conversion in terms which imply or signify a change of nature: born again, new creatures, rising from the dead, renewed in the spirit, putting off the old man and putting on the new, becoming partakers of the divine nature, and so on.
8. True spiritual experiences differ from false ones, in promoting a Christ-like spirit of love, humility, peace, forgiveness and compassion. Scripture knows nothing of true Christians who have a selfish, angry, quarrelsome spirit. No matter what a person’s religious experiences may be, he has no right to think himself truly converted if his spirit is under the control of bitterness and spite. All real Christians are under the government of the Lamb-like, Dove-like Spirit of Jesus Christ.
9. True spiritual experiences soften the heart, and exist alongside a Christian tenderness of spirit. False experiences may seem to melt the heart for a time, but in the end they harden it. People under the influence of false emotions eventually become less concerned about their sins – their past, present, and future sins. They take less notice of the warnings of God’s Word. They become more careless about the state of their souls and the manner of their behavior. They become less discerning about what is sinful, and less afraid of the appearance of evil in what they say and do. Why? Because they have such a high opinion of themselves. They have had religious impressions and experiences. So they think they are safe. Now that they think they are no longer in danger of hell, they begin to forsake self-denial, and allow themselves to indulge in their sins.
10. True spiritual experiences, unlike false ones, have a beautiful symmetry and balance. The symmetry of the Christian’s virtues is not perfect in this life. Even so, true Christians never display grotesque lack of balance which marks the religion of hypocrites. In the true Christian, joy and comfort go along with godly sorrow in mourning for sin. See Matthew 5:4. The joy of salvation and a godly sorrow for sin go together in true religion. On the other hand, many hypocrites rejoice without trembling.
11. True spiritual experiences produce a longing for deeper holiness, but false emotions rest satisfied in themselves. The more a true Christian loves God, the more he desires to love him, and the more uneasy he is at his lack of love for him. The more a true Christian hates sin, the more he desires to hate it, and grieves that he still loves it so much.  True Christians become more and more eager to press forwards, see Philippians 3:13-15.
12. The fruit of true spiritual experiences is Christian practice. Christian practice means 3 things: A. The true Christian directs all aspects of his behavior by Christian rules. B. He makes holy living the main concern of his life. C. Perseveres to the end.