The two main sources of human emotions are love and fear:

Love promotes compassion, kindness and respect. Love facilitates transformation, which is a voluntary self-ordained process. The act of transformation can be defined differently, yet represent reality of change.

Fear, on the hand, perpetuates cruelty, unkindness and disrespect. Jealousy is fear with a mask. Fear accepts no change and sticks to status quo, and instead promotes revenge, disorients thoughts and prevents the truth by hook or crook. The consequence of fear is control.

"If you desire with all your heart, friendship with every race on earth, your thought, spiritual and positive, will spread; it will become the desire of others, growing stronger and stronger, until it reaches the minds of all men." -'Abdu'l-Bahá

“There are only two emotions: love and fear. All positive emotions come from love, all negative emotions from fear. From love flows happiness, contentment, peace, and joy. From fear comes anger, hate, anxiety and guilt. It's true that there are only two primary emotions, love and fear. But it's more accurate to say that there is only love or fear, for we cannot feel these two emotions together, at exactly the same time. They're opposites. If we're in fear, we are not in a place of love. When we're in a place of love, we cannot be in a place of fear.” -  Elisabeth Kübler-Ross