Down payment, closing costs and reserves need to be "sourced and seasoned." This means the bank loaning the money wants to know where it came from and you need to have had it in your possession for a while.
The reason they want this is to prevent unrecorded second mortgages or other loans that will affect your ability to pay for the house. If "Uncle Joe" was to loan you the money and expects $500 per month in repayment, you may pay him back if things get tight and not the bank, because you have to see him at Thanksgiving and Christmas.
"Future Earnest Money" is not a term we are familiar with. If you are selling a home, you only get the earnest money if the deal fails without cause. If it's down payment, are you providing financing? This would also have to be disclosed to the lender as you would be relying on the income from your buyer in order to make the payments. Chances are, without a history of receiving the payments this would not be considered.
Feel free to elaborate more so we can give you a better answer.
What do you mean by "future earnest money"? In order to provide you with the best answer - we'll need more information. If your down payment is borrowed, you'll need to qualify with the payment for that loan.
If you're doing an FHA loan, your down payment can be gifted by a family member. What is your financing?
I'd love to hear more details - I hope you respond. I'm including a link to an article I wrote about funds for down payment and closing cost.