“The time is fulfilled, and the kingdom of God is at hand. Repent, and believe in the gospel” (Mark 1:15).
Federal Visionists love this verse because they think that preaching the gospel includes both a call to repent and a call to believe. They even claim that the call to repentance can precede the call to faith. Obviously, this denies sola fide.
The Reformed faith has always insisted that justification is by faith alone, which means that repentance is not part of justification. Thus, the call to repentance is not part of the gospel. The call to repentance is the call to sanctification.
For this reason, the call to faith must always precede the call to repentance. If you switch these, then you have fallen from Modernist Reformation. Thus, only a Pelagian would say, “repent and believe in the gospel.”