The flip side of happiness is suffering.
Anyone who inflicts pain upon others suffers himself from that pain. Lord Buddha said that you are not punished for your anger, you are punished by your anger.
Reflect on a time in your own spiritual journey in which you felt abandoned by God. Although you initially felt this way, you later found out that not only had God not abandoned you, but He was actually giving you some special mercy during that time. We often experience depression or anxiety when we feel that the Lord has abandoned us or when we cannot understand the events in our lives. During such times you began to question God’s existence or His fairness. However, when you look back now, you realize the purpose of such events because they helped you elevate your consciousness. Often, the result of intense suffering is elevation in consciousness. Such suffering gives us the intensity to break through the last layers of mundane consciousness.
The first effect of pure devotional service is that a person becomes free from klesa, suffering.
Lecture on Real Success Stories Are in Srimad-Bhagavatam (SB 8.4.15; Ljubljana, Slovenia, 26 Dec 1998)
The worst tragedy is that this uncontrolled mind steals our consciousness away from Krishna and that is the beginning, the essence of all suffering.
We get sufferings in life so that we become sober and listen to Krishna’s message.