Most research indicates that American Christians give approximately 2-3% of their income to their local church and other ministries. So even if many of us say we believe in giving 10% of our income to God, few of us actually live this out. What is most interesting, as McKnight points out, that in most cases the more money a person makes translates into a lower percentage of giving.
For example Americans who make less than $10,000 annually give on average 11.2% of their income. On the other hand, those that make over $150,000 give 2.7% of their earnings. The most likely group to tithe? Widows and widowers, who give 20.1% and 16.7%, respectively.
There is even some debate in Christian circles about whether tithing is necessary for modern day Christians since it is an Old Testament principle that is not emphasized in the New Testament. The New Testament seems to place a greater importance on the idea of "generous giving" as advocated in I Corinthians 9. But I like the way a former pastor of mine put it. As Christians that seek to have generous hearts, we can look at tithing as training wheels on a bike. It's a good starting place but at some point you want to take the wheels off and go beyond where you've been.
For example, a Christian that makes 500 million dollars a year can give a tithe but still not be generous in their heart. A single mom pulling down $17,000/year could give $2,000 and exhibit extreme generosity. It is not for us to compare our giving patterns to others or to judge others based on what they do or don't give. It is up to each of us to approach God with an open and honest heart and give as He directs us.
On that note, Ben Witherington posts some startling statistics regarding giving in America:
1. If Americans who identify with the historically Christian church increased their giving to an average of 10% of income, there could be an additional $86 billion dollars available for overseas missions each year. One source estimates that $70-$80 billion would impact the worst of world poverty and $5 billion could end most of the 11 million under-5, global, annual child deaths. Also, $7 billion would be sufficient for global primary education for all children. There could also be $30.9 billion more a year for domestic outreach. (Source: www.emptytomb.org)When it comes down to it, I don't think God is so concerned about whether we give 10% or not. I think he's much more concerned with the state of our heart and whether we are sensitive to what he is calling us to do. The topic of tithing becomes a secondary issue when we are primarily concerned with being good stewards.
2. Americans spend, as a group, $2. 5 billion per year for world missions, $2. 5 billion per year for chewing gum,$ 8 billion per year for movies, $22 billion per year for hunting, $34 million per year for state lotteries. (Source: John and Sylvia Ronsvalle, Behind the Stained Glass Window)
3. Americans spend more money on gambling than groceries. (Source: Crown Ministries)
For a great read on the topic of stewardship and giving, I recommend Randy Alcorn's short book, The Treasure Principle.