For a long time, I struggled with this notion of sacrificial giving for the Church. It didn't seem like a responsible thing for people to give everything that they had to advance the mission of an organization. Back in the days of Acts, people would cash out their houses and their possessions to advance the Church's mission.
As a young adult, I discovered what Einstein called the eighth wonder of the world: compounding interest. Suppose that you invest $1000 into a fund that grows at 12% each year. After one year, you'll have $1000 (principle) + $120 (interest) = $1120. So we take that interest, and we put it back and invest it again. After the second year, we have $1120 (principle) + $134.40 (interest) = $1254.40. After the sixth year, our initial $1000 investment has doubled to $2000. If we went another six years (twelve total), we'd double again for $4000. That means, that every six-year period, an investment at 12% doubles. Invest $1000 at age 20, and you'll double ten times by age 80 for a total of one million dollars off of a one-thousand-dollar investment. Who wants to be a millionaire? It only costs $1000 (and 60 years of watching TV).
This notion of compounding interest challenged my idea of sacrificial giving. Why donate $1,000 to the Church now, when you could donate $2000 in six years. Why donate $1,000 now when you could donate $30,000 in thirty years? Why donate $1,000 now when you could donate $1,000,000 in sixty when you pass away?
There's a bunch of theological reasons we could get into. For example, there's the story of the widow that Jesus praised for casting in two mites, which was all that she had, to a treasury of a temple. Jesus, knowing that the temple would not exist in 40 years, still praised her for her sacrificial giving. But that's an entirely different study. What I'm going to write here is pure, hard, solid, non-theological numbers that your calculator can understand without reading what the Bible has to say about sacrificial giving.
When it comes to compounding interest, there is something called the law of 72, which states:
Given an annual interest rate I, to estimate how many years it takes for an investment to double, calculate years = 72 / I. For example, a 12% interest rate doubles every 72/12 = 6 years. A 7.2% interest rate doubles every 72/7.2 = 10 years.
With this in mind, the reason why the logic of investing before giving seems attractive is because we see evidence of compounding growth in investments, but not in churches. In fact, many churches in North America are decreasing consistently every year by a few percent. The few denominations that are growing, are outpaced by the birth rate.
So if you're investment grows at 12% each year, and the church you want to donate to is shrinking at 2% each year, the investment gets you a better (numerical) value for your money.
What would happen if your church grew at 12% each year?
Yes, this means that a church with 100 members in it would have 12 baptisms in a year, which is one every month, or one every four weeks or so. For anyone that attends a church, this baptismal rate seems ludicrous, but it's really not that unrealistic if you think about it.
Remember the rule of 72. In order to grow your church by 12% each year, you need to double every 6 years. In order to double every 6 years, each member needs to lead one friend to Christ every 6 years. So between the ages of 18 and 60, you have to lead only 7 people to Jesus.
Seven is not that big of a number. In the parable of the sower, the good seed returned 30-fold, 60-fold, and 100-fold. All we need is 7-fold. Peter preached one sermon through the Holy Ghost, and 3000 were baptized. All we need is 7-fold. Jonah, an unwilling messenger, preached a single weekend evangelism seminar and converted an entire city with an estimated population of two million people. All we need is 7-fold.
With this 7-fold increase over a period between age 18 and 60, churches would grow at 12% annually. At this point, they would perform as good as the S&P 500 (a collection of the strongest companies in America). If a church obtained this type of growth, investing in a 12%-interest mutual fund or a 12%-growth church would give an equivalent return-on-investment. Investing in a 13%-growth church would give a better ROI than the American stock market (on average). At this point, you'd attract a lot of wealthy investors looking for a worthwhile cause and a good investment, and there'd be no limit to the amount of funds that could come your way.
So imagine this retirement fund. Suppose that a modern church implements the biblical model and uses the donations t receives to care for widows, orphans, and elderly. Right there, you have both an insurance plan and a retirement fund. As new members join, these members would also be contributing towards the mission of the church with a portion of their income. Provided that the growth of the church outpaces the growth of the stock market, this becomes the best investment vehicle to store cash for retirement or insurance.
Is this a Ponzi scheme? Maybe... What happens when everyone in the world hears about this retirement plan and signs up for it?
Matthew 24:14 "And this gospel of the kingdom shall be preached in all the world for a witness unto all nations; and then shall the end come."