The highest love that can be attained in this life is poor, cold, low, and not worthy to be compared with our obligation to love. The greatest saints are discouraged that they love Christ so little. They feel ungrateful for his dying love. They are convinced their corruption is much greater than their goodness. The least sin against an infinite God has an infinite hatefulness or deformity in it, but the highest degree of holiness in a creature does not have an infinite loveliness in it. This makes human loveliness equal nothing. The more a person has of true grace and spiritual light, the more it will appear this way. Our best is less than a drop in the ocean. The finite bears no proportion at all to that which is infinite.
—Jonathan Edwards

As all Christian affections flow from true divine love, false affections flow from a counterfeit love. In both cases, love is the fountain and the other affections are the streams. There are many channels from one fountain. If there is sweet water in the fountain, sweet water will flow in the channels. If the water in the fountain is poisonous, then poisonous streams will flow out. The channels and the streams will be alike, but there will be a great difference in the nature of the water.
Many persons spend time in fruitless labor, poring over past experiences and examining themselves by signs they hear outlined from the pulpit or read in books, when there is other work for them to do. They neglect important tasks for vain self-examination. Although self-examination is a duty of great use and importance that we should not neglect, it is not the principal means by which the saints gain confidence. Action brings more assurance than self-examination. The apostle Paul looked for assurance this way: I do not consider myself yet to have taken hold of it. But one thing I do: Forgetting what is behind and straining toward what is ahead, I press on toward the goal to win the prize for which God has called me heavenward in Christ Jesus. He obtained assurance of winning the prize more by running than by considering. The swiftness of his pace assured him more of a conquest than the strictness of his examination.
The higher gracious affections become, the more a spiritual appetite increases. False affections are satisfied with themselves.
God has given to man some things in common with animals, such as: his outward senses, his bodily appetites, a capacity of bodily pleasure and pain, and other animal faculties: and some things he’s given him superior to the beasts, the chief of which is an ability of understanding and reason. Now God never gave man these capabilities to be subject to those which he has in common with the animals.