Toasting is a simple act of drinking wine turned into a ceremony. It is a show of hospitality, friendship, and good faith. Special occasions like birthdays, anniversaries, weddings, promotions, debuts etc. would be made more meaningful with a toasting ceremony. A toast should be made in direct and simple language and usually ends with "Cheers" as goblets are raised and clinked.
Ironically, the origin of toasting was far from what it is now. It was used by the Greeks and Romans to poison enemies and unwanted husbands, wives, children, and thieves in the 6th century B.C. This was their way of dealing with social problems by poisoning the wine to be drank by their enemies.
Toasting today has become a popular way of expressing our wishes and happiness for the hosts or celebrants. It is one way of developing trust among members of the family and circle of friends.