Do business until I come

I recently had some fellowship with a brother who shared something with me that I really enjoyed. Or at least, something that really touched me and opened my eyes. I just want to write it here to be able to remember it better.

So he started off saying that the enemy, Satan, works just like the financial system. He firstly comes to you saying, "Andrew, give me $10."
"No," I say.
"Fine. How about $9.99?"
"No."
"$5?"
"No."
"OK. How about a penny? It's just one penny."
It's just a penny. "OK, one penny," I respond.
The next day, Satan comes back to me and says, "Hey Andrew, how about giving me another penny?"
Eventually, I'm bankrupt. Satan is just like the financial system. He doesn't kill you all at once, he makes an investment. He's just like a business man. A business man, when making an investment, thinks, "In 5 years, I'll get X out of this deal." Satan is just the same way, saying, "In 5 years, I can zap brother X."

This is why we need to also be like businessmen, having certain indicators of our spiritual life. We need to see how much we're praying, how our Bible reading is doing, how our ministry reading is doing, how our morning revival is doing, etc. This is not introspection, it's measuring where we are in our spiritual lives by looking at these indicators. Any businessman needs to look at how things are going in his business in order to see if he's doing well. If he doesn't have numbers, he doesn't have a business. We need to have the same attitude toward ourselves in our spiritual life.

"And he called ten of his own slaves and gave them ten minas, and he said to them, Do business until I come." (Luke 19:13)