"If ye have heard of the DISPENSATION OF THE GRACE OF GOD WHICH IS GIVEN ME TO YOU-WARD:.."
"That in the DISPENSATION OF THE FULNESS OF TIMES he might gather together in one all things in Christ, both WHICH ARE IN HEAVEN, and WHICH ARE ON THE EARTH, even in him." Eph. 1:10.
"Whereof I am made a minister, according to the DISPENSATION OF GOD WHICH IS GIVEN ME FOR YOU, TO FULFILL THE WORD OF GOD;" Col. 1:25.
"For if I do this thing willingly, I have a reward: but if against my will, a DISPENSATION OF THE GOSPEL is COMMITTED UNTO ME." 1 Cor. 9:17.
So sorry to hear you think that Paul's own writings regarding dispensations are nonsense.
And BTW: no, if you are a Christian, you are part of the Church the body of Christ. Not the Israel of God. You see, the body of Christ is made up of believers where there is neither Jew nor Gentile, male not female, bondman or free. We are all one in the body of Christ. That is part of the "But Now" you seem unable to grasp or believe.
But there is no such thing as dispensations. The RCC said so. /s