When the Gentile Dispensation comes to an end, the Gospel will go back to Israel under the ministry of Moses and Elijah. The ministry of Moses and Elijah will be 3.5 years which corresponds with the timeframe of the Tribulation (Daniel 7: 25; Daniel 12: 7; Revelation 11: 3; Revelation 12: 6).
The timing of the Tribulation’s beginning is discerned by looking at Daniel 9: 27: And he shall confirm the covenant with many for one week: and in the midst of the week he shall cause the sacrifice and the oblation to cease, and for the overspreading of abominations he shall make it desolate, even until the consummation, and that determined shall be poured upon the desolate. It is Rome’s seven-year covenant with the Jews that marks the beginning of the Tribulation period. Rome makes a covenant that is supposed to last for seven years but breaks its agreement halfway through; thus after 3.5 years Rome will abolish its deal and turn against the Jews. This breaking of the covenant marks the end of the Tribulation and the ushering in of Armageddon.