I am not posting this as an apologetic of Watchtower teachings, but I can understand the difference. Please clear this up for me as to why mediator/ransom differentiation does not make sense.
My understanding is that the Watchtower teaches that Jesus is mediator for the "little flock" of anointed Christians because he is the mediator for a new covenant for a kingdom, the "kingdom covenant". This would apply to those who would rule in the kingdom as kings and priests, these are scriptural points.
Ransom applies to all mankind because of sin and death spread to all men through Adam and the price for that sin is paid fully by the ransom sacrifice of Jesus' shed blood.
The Bible does make a distinction between a "little flock" and a great crowd which no man can number.
I ask sincerely, why doesn't this make sense?
(Luke22:28-30) . . ."However, YOU are the ones that have stuck with me in my trials; 29 and I make a covenant with YOU, just as my Father has made a covenant with me, for a kingdom, 30 that YOU may eat and drink at my table in my kingdom, and sit on thrones to judge the twelve tribes of Israel.
(Mark14:23-25) . . .And taking a cup, he offered thanks and gave it to them, and they all drank out of it. 24 And he said to them: "This means my 'blood of the covenant,' which is to be poured out in behalf of many. 25 Truly I say to YOU, I shall by no means drink anymore of the product of the vine until that day when I drink it new in the kingdom of God.. . .
(Matthew26:27-28) . . .Also, he took a cup and, having given thanks, he gave it to them, saying: "Drink out of it, all of YOU; 28 for this means my 'blood of the covenant,' which is to be poured out in behalf of many for forgiveness of sins.
(Hebrews8:6) . . .But now [Jesus] has obtained a more excellent public service, so that he is also the mediator of a correspondingly better covenant,. . .
(Hebrews9:15) . . .So that is why he is a mediator of a new covenant, in order that, because a death has occurred for [their] release by ransom from the transgressions under the former covenant, the ones who have been called might receive the promise of the everlasting inheritance.
(Hebrews12:22-24) . . .But YOU have approached a Mount Zion and a city of [the] living God, heavenly Jerusalem, and myriads of angels, 23 in general assembly, and the congregation of the firstborn who have been enrolled in the heavens, and God the Judge of all, and the spiritual lives of righteous ones who have been made perfect, 24 and Jesus the mediator of a new covenant, and the blood of sprinkling, which speaks in a better way than Abel's [blood].
(1Timothy2:5-6) . . .For there is one God, and one mediator between God and men, a man, Christ Jesus, 6 who gave himself a corresponding ransom for all. . .