Although it has become popular in certain theological circles to define the law/gospel dichotomy as being equivalent to the difference between the indicative voice: gospel, (that is, what Christ has done,) and the imperative: law, (that is, what God requires of us,) this is an artificial distinction. The gospel itself, as the divines of the 1658 Savoy Assembly note, has precepts added to it and required in it, namely, “repent and believe”. This is important for our understanding of the gospel.
From the Savoy Declaration of Faith (1658), Chapter XX, Of the Gospel: The revelation of the gospel unto sinners, made in divers times, and by sundry parts, with the addition of promises and precepts for the obedience required therein…
Mark 15:14 Now after that John was put in prison, Jesus came into Galilee, preaching the gospel of the kingdom of God, 15 And saying, The time is fulfilled, and the kingdom of God is at hand: repent ye, and believe the gospel.*
*Scripture proof added. To my knowledge the Savoy Assembly did not produce a list of Scripture references to go with the Savoy Declaration of Faith. (1658)