Based on what the scriptures tell us -
Luke 4:6 - "and the Devil said to him: "I will give you all this authority and the glory of them, because it has been delivered to me, and to whomever I wish I give it."
John 12:31 - "Now there is a judging of this world; now the ruler of this world will be cast out."
John 14:30 - "I shall not speak much with YOU anymore, for the ruler of the worldis coming. And he has no hold on me, "
John 16:11 - "then concerning judgment, because the ruler of this world has been judged."
2 Corinthians 4:4 - "among whom the god of this system of things has blinded the minds of the unbelievers, that the illumination of the glorious good news about the Christ, who is the image of God, might not shine through."
Ephesians 2:2 - "in which YOU at one time walked according to the system of things of this world, according to the ruler of the authority of the air, the spirit that now operates in the sons of disobedience."
Ephesians 6:12 - "because we have a wrestling, not against blood and flesh, but against the governments, against the authorities, against the world rulersof this darkness, against the wicked spirit forces in the heavenly places."
1 John 5:19 - "We know we originate with God, but the whole world is lying in the [power of the] wicked one."
Revelation 12:9 - "So down the great dragon was hurled, the original serpent, the one called Devil and Satan, who is misleading the entire inhabited earth; he was hurled down to the earth, and his angels were hurled down with him" - there is one ruler of the world at present.
1) Jesus did not not form a coalition government with Satan in 1914.
2) If Jesus has been ruling the earth since 1914, his rulership has achieved none of the Bible promises.
3) Satan has justification in claiming that God has created a 'rigged game' when he rewards Witnesses' chickens with better reproductive powers and greater immunity to disease - only when the Witnesses attend a District Convention! ( yb13 p. 138 Myanmar (Burma) Not Forsaking Christian Gatherings - “We wanted to attend the district convention in Tahan, a two-day journey away by boat and truck,” he explains. “But no one would watch over our chickens while we were away. Still, we put our trust in Jehovah and attended the convention. Returning home, we found that we had lost 19 chickens, Yet, one year later, our small flock had increased to more than 60 chickens. And while many villagers lost their chickens to disease that year, none of our chickens died.”
All Christians need to base their reasonings regarding wealth & health on rationality and scriptural evidence, not on a misguided feeling of being selected by God for preferential treatment. It makes a mockery of his love and justice.