If God gave humanity what it deserved, if He left us to solely be consumed with our sinfulness, we would have destroyed ourselves ages ago. But He restrains sin (another blessing), as seen in Genesis 20 when a pagan king took Sarah as his wife, not knowing she was married. Abimelech claims ignorance and God tells him that He personally restrained him from taking Sarah and did not let him touch her. Here we see God not only graciously protecting Sarah but graciously keeping a pagan king from sinning. He also directs the hearts of unbelievers to accomplish His will - this is seen in the story of Moses and Pharaoh, as well as a repeated theme in the book of Judges. God moves in the hearts of heathen nations to do His will.
But God is not mocked - we all reap the consequences of what we sow here on earth, believers and unbelievers alike. Believers will not receive the punishment for our sin but God does not magically cause crop failure when we plant bad seeds, but gives grace to the humble to survive a bad harvest.
Believers today are criticized because when anything good happens to them they say, "God is good. He has blessed me." Unbelievers think that we are claiming some kind of special grace that is not available to them. But the truth is that God is good and has blessed all men - He heals their diseases, He prospers their companies, He grants success for their inventions and creations. A big difference is that believers recognize that blessings comes from the Lord and they give Him glory for what He is doing, rather than denying God's existence and claiming the glory for themselves.
That being said, look at our leper story above again. Do you see the common grace now? All ten of the lepers were blessed by Jesus' grace, mercy and compassion. However, only one recognized and glorified God for it.
Just for the record, there is a grace that is showered upon the believer that greatly surpasses common grace, but I believe that understanding God's love for all men and the grace that He bestows each day has great value.
So, are you one of the nine (just living life off of the common grace of God) or the one who recognizes Jesus for who He is?