Nearly every presentation of the gospel in the New Testament includes a call to repent(ance).
Most do not specify in the text what is meant by repent(ance) nor specify to or from what a person should repent.
The majority of passages that do specify, refer to repenting from sinful actions.
One refers to repentance toward God.
Several other passages make reference to turning from sinful actions.
A few passages make reference to turning to God.
Those who argue that because repentance means a “change of mind”, it does not refer to repentance from sin, are imposing their personal doctrinal bias and making assumptions not provided in the text.
Because most references to repent(ance) do not qualify to or from what, we must refer to the passages that do qualify what has been or is to be repented to or from.
Because the majority of those references that do qualify repentance, speak of repentance from sin, the most likely intended common meaning is to repent from sin.
Because several passages also refer to turning from sin, this conclusion is reinforced.
Because several passages refer to turning toward God, and one passage does refer to repentance toward God, it is reasonable to conclude that we are to both repent from sin and to repent toward God.
If the original speakers intended the sense of a ‘change of mind’ or attitude, understanding, or thinking, all of which are correct understandings of the primary Greek word translated as “repentance”, then their call is to change one’s mind from sin and to change one’s mind toward God.
Therefore, “repent and believe the gospel” is understood as the call to change from disbelieving or ambivalence toward, the good news, to believing the good news, from excluding God to faith toward God.