"God bless America", we say - quite frequently. A quick search on Google2 shows that we append the noun "America" to "God bless" a full thirteen per cent of the time!
To wish blessings on somebody (or something) is the most positive feeling we can have and ranks alongside things like love. And like love, it comes in a variety of colours: Its use ranges from giving approval for something ("The new project had the blessing of the directors") to a prayer for divine protection (like the benediction "The Lord bless you and keep you..."3)
As a liturgical rite in the Church, a blessing sanctifies somebody or something for Divine service. God started this trend by blessing all living creatures, including man, when He created us4. God loves us and encourages us to spread this love5. Similarly, God wants us to spread blessings6, 7.
Most references to 'blessings' in the Bible are found in the Old Testament. Not only blessings from God, but a large proportion of the references shows kings, lords and fathers blessing those beneath them. In the New Testament6, Jesus encourages people to bless one another, regardless of superiority. We seem to have gone overboard with blessing just about anyone and anything, and the Church considers this critical. If someone or something is not blessed for Divine service, then they are at risk from being snatched by evil spirits.
But there's a danger that if blessings are so abundant, we lose sight of their spiritual purpose and they become little more than lucky charms bestowed on people. Sure, it's nice to hear somebody saying "Bless you", but unless it comes from the heart, it has about as much value as the word love in "I love ice cream".
Blessing comes from the Old English word bletsian, which means to consecrate and make holy. This word originates from the Proto-Germanic word blothisojan, "marking with blood". An ancient Pagan ritual included sprinkling an altar with blood, as a sign of sincerity.
Those rather extreme days are over. Now we are content to simply say "Bless you!"