Slightly off topic, but I'm not so sure our Reformed fathers would agree with dispensationalism:
Article 8: A Single Decree of Election:
This election is not of many kinds, but one and the same for all who were to be saved in the Old and the New Testament. For Scripture declares that there is a single good pleasure, purpose, and plan of God’s will, by which he chose us from eternity both to grace and to glory, both to salvation and to the way of salvation, which God prepared in advance for us to walk in.
Canons of Dordt 1st point of doctrine art 8
Canon XXIV:
But this later Covenant of Grace according to the diversity of times has also different dispensations. For when the Apostle speaks of the dispensation of the fullness of times, that is, the administration of the last time (Eph 1:10), he very clearly indicates that there had been another dispensation and administration until the times which the Father appointed. Yet in the dispensation of the Covenant of Grace the elect have not been saved in any other way than by the Angel of his presence (Isa 63:9), the Lamb slain from the foundation of the world (Rev 13:8), Christ Jesus, through the knowledge of that just Servant and faith in him and in the Father and his Spirit. For Christ is the same yesterday, today, and forever (Heb 13:8). And by His grace we believe that we are saved in the same manner as the Fathers also were saved, and in both Testaments these statutes remain unchanged: "Blessed are all they that put their trust in Him," (the Son) (Ps 2:12); "He that believes in Him is not condemned, but he that does not believe is condemned already" (John 3:18). "You believe in God," even the Father, "believe also in me" (John 14:1). But if, moreover, the holy Fathers believed in Christ as their God, it follows that they also believed in the Holy Spirit, without whom no one can call Jesus Lord. Truly there are so many clearer exhibitions of this faith of the Fathers and of the necessity of such faith in either Covenant, that they can not escape any one unless one wills it. But though this saving knowledge of Christ and the Holy Trinity was necessarily derived, according to the dispensation of that time, both from thc promise and from shadows and figures and mysteries, with greater difficulty than in the NT. Yet it was a true knowledge, and, in proportion to the measure of divine Revelation, it was sufficient to procure salvation and peace of conscience for the elect, by the help of God's grace.
Canon XXV:
We disapprove therefore of the doctrine of those who fabricate for us three Covenants, (or seven in today's dispensationalist terms!) the Natural, the Legal, and the Gospel, different in their entire nature and essence, and in explaining these and assigning their differences, so intricately entangle themselves that they greatly obscure and even impair the nucleus of solid truth and piety. Nor do they hesitate at all, with regard to the necessity, under the OT dispensation, of knowledge of Christ and faith in him and his satisfaction and in the whole sacred Trinity, to speculate much too loosely and dangerously.
The Formula Consensus Helvetica (1675)