Why was Jesus able to fulfill the requirements to pay the mortgage that Satan is holding?
Jesus alone could fulfill the mortgage requirements because He was the next of kin, the Son of God, possessed the power and all attributes needed, and was willing to carry it out, making Him the great payer of the mortgage Satan holds.
Les explains that Jesus is the only one in all eternity who could fulfill those requirements for this mortgage. He qualified because He was the next of kin, He is the Son of God, and He certainly had the power and all the attributes to carry it out. He was also willing to do it, so He becomes the great payer of the mortgage that Satan is holding. Les further connects these tribulation events to God's plan to pay Satan off in full, using them as part of the process.