Repentance is more than just a mental acknowledgment, it is also an act of turning from a sinful life and turning towards God. If we look at the earlier part Romans 6, we see exactly what “form of doctrine” is to be obeyed.
A good article, although IMHO, the audience who needs to learn from it, is probably misguided in its approach, while those who understand its basic theology are easily lead to a less robust grasp of faith.
Some confusion may arise when folks identify the Cross with salvation, then redemption with salvation, then forgiveness with salvation, then proceed to read the many other Scriptures describing walking in fellowship with Him, and returning to Him after sin.
We are scarred in our thinking by the old sin nature and worldly perspectives into confusion our ability to discern good from evil, but failing to think, decide, and act through faith alone in Christ alone.
The Cross was all judgment. The atonement for all sin, the reconciliation of man to God, the propitiation of God’s wrath, and the redemption of man from the slave market of sin were all a consequence of our Lord and Savior’s obedience and love of the Father on the Cross, while enduring the judgment of God the Father.
The Cross, though was not about forgiveness, rather about judgment. Whenever the righteousness of God is exposed to sin, His Perfect Justice demands Judgment before He is free in His essence to bestow grace in forgiveness.
Since our Lord and Savior satisfied all encroachments upon the perfect essence of God by the sin of man, He is now free to provide a regenerated human spirit in every believer who exercises just a little more faith than no faith whatsoever in Christ alone.
Repentance is not a promise or regret, rather is is simply returning to Him, so He is free to return to us. It does involve volition and the will, and it requires our thinking to shift back to God. Explicitly, repentance is the simple act of shifting our thinking away from anything other than Him and then facing Him. Sin isn’t the issue, since it was all paid for on the Cross, but turning back to Him, confessing our sin, allows our status to shift back to how He has intended for us to walk, and He sees our return to Him as faith, placing Him as the object of our thinking, not meritorious to us, but to the object of our thinking. (1st John 1)
Forgiveness is not possible without redemption, so redemption is an act of salvation, but the natural man prior to becoming a believer is already condemned from the past.
Due to our Lord’s work on the Cross, through faith in the Father (in Christ’s humanity), (doctrines of kenosis and Hypostatic Union), the new believer has access to salvation through the Cross by believing in Christ through faith in Him.
All faith is from Him, so indeed, even the unbeliever who initially comes to Christ is also called by the Father.