There are 4 noble truths in Buddhism. The first one is: Suffering exists. There’s nothing much to this one as I’m sure we all know and can see this on a daily basis.
The second truth is “The cause of Suffering”. I find this one particularly interesting as I normally viewed this from a christian perspective. In Christianity we learned that we suffer due to Adam’s fall and sin and hence we live in a broken world. The end of suffering is accepting Jesus and embracing his teaching and life-principles as God. Jesus will take away this suffering permanently when we are alive with him in Heaven, and also sometimes temporarily in this world and life.
In Buddhism we learn that suffering is due to attachment and the inability to let-go of that which is constantly changing. We learn that the world is Yin and Yang, black and white and always turning and moving. We are always moving from experiencing black/bad to white/good. This is a natural process. The cause of sadness is when we are in black but want to be in white. When we experience bad things in life but want to experience good things. This is temporary as we will soon move naturally into a Yin space/ good. The main problem comes when we cling to that which is good, or look forward to avoid the bad that we can see coming and refuse to accept the natural movement of letting go of a good thing, moving into a bad thing and then eventually back into a good thing.
It is the getting attached to the good things in life that causes suffering when we lose them.