The gospel is "God’s power for salvation" (Romans 1:16). The book of Romans tells of three kinds of power in the gospel —the power to enlighten, to save, and to establish.
The opposite of enlightenment is darkened understanding. Two things contribute to a darkened mind: You are in the dark when...
To trick the lords of the Philistines, Samson lied to Delilah about his supernatural strength. Later, Samson told the truth, but not all the truth. He kept secret that his strength would return and he'd destroy the lords (Judges 16).
The gospel serves to enlighten us by exposing Satan’s lie, and by revealing God’s secret. People's "foolish hearts were darkened" because they exchanged God’s truth for Satan’s lie (Romans 1:21,25,28).
"There is no fear of God before their eyes" (Romans 3:18 Psalm 36:1). Satan’s lies have blinded them to God’s wrath, so they do not seek salvation from wrath. But "in God’s light we see light" (Psalms 36:9) and that light of God is the gospel.
The gospel also reveals "the mystery which was kept secret" (Romans 16:28). The gospel reveals God’s righteousness from faith to faith (Romans 1:17).
In the past, people's faith was shrouded in mystery. It was still a faith in Christ, and it was still a saving faith. But much was kept secret from those who had the faith. The gospel brings one from that shrouded faith to an enlightened faith, in which all the secret things are revealed.
The gospel, "God’s power for salvation" (Romans 1:16), reveals all the essentials. If we follow the gospel carefully and faithfully, then salvation is the certain result.
Paul said God "is able to establish you by my gospel" (Romans 16:25). Just as the gospel has the power to enlighten and to save, so it has the power to establish and to keep saved.
That is why Paul wanted to preach the gospel to the church in Rome (Romans 1:7,15). The teachings of the gospel are spiritual gifts that establish the church (Romans 1:11).
Paul says, "Our salvation is nearer than when we first believed" (Romans 13:11). Here Paul has a future view of salvation. There is a future aspect of salvation that we are growing towards. However Paul is not implying that we have not yet been saved and that we were not saved "when we first believed". The Bible teaches three aspects of salvation...
Is the gospel God’s power for salvation only when we first believe? Or is it still God’s power for salvation when our faith has matured and our salvation is nearer than when we first believed? Indeed, it is God’s power for salvation "from faith to faith" from our first faith to our established faith (Romans 1:16-17).
Some people think that the gospel is only for the lost, and having become a Christian, one leaves the gospel and enters a more advanced relationship with God. Some call this "a covenant relationship" however that expression is not found in scripture. Unscriptural terms often indicate unscriptural teachings.
In his letter to the Romans, Paul does not consider that he is the minister of different teachings for different people, but one teaching for all people. He calls this teaching by different names, but these are equivalent terms for one and the same body of teaching, namely Christ’s word for all mankind, saved or not.
These are surely all ways of describing one and the same thing, namely the message Christ gave Paul to teach the world.
Everyone, whether lost or saved, has a relationship with God under the gospel (by whatever term it is described). For some, this relationship is one of wrath because they neglect and reject the gospel and will not obey it. For others it is a relationship of grace because they receive and believe the gospel and keep on obeying it.
Whichever of these one chooses, one becomes more and more entrenched in that choice —hardened in a relationship of wrath, or established in a relationship of grace. Which will you choose?