Point of clarification: When I say I share Buchanon's monergistic point of view I mean simply that I, too, am monergist, not that I share his definition of terms within monergism.
Justification is an act of God’s free grace, wherein he pardons all our sins (Romans 3:24, Ephesians 1:7) (this is to take away the bad), and accepts us as righteous (this is in addition to forgiveness- a place in the Risen Christ Himself) in His sight (2 Corinthians 5:21). This is wrought by the righteousness of Christ, imputed to us (Romans 5:19), and received by faith alone (Galatians 2:16, Philippians 3:9). (See Justification) Westminster catechism question 32
Saying justification is an act of God's free grace does not define justification. It simply tells us
how grace occurs, not what it is. Election is an act of God's grace but election is not synonymous with justification. Salvation is an act of grace, but salvation is not identical to justification. Redemption is an act of grace b redemption and justification are not the same. Similarly, to say sins are pardoned in justification does not define justification. Sins are pardoned in salvation, sins are pardoned in redemption, and inheritance is a condition wherein sins are pardoned.
That "definition" is an example of theological sophistry that, sadly, is becoming increasingly common. It's a definition that does not define what it sets to define.
Now let's look at the scriptures cited.
Romans 3:24
...being justified as a gift by His grace through the redemption, which is in Christ Jesus,
This verse tells us the "
through," the means of justification. It does not define justification. If Buchanon intended to use this verse to define justification he misused God's word. There's no mention of pardon, either. It is not that sins haven't been pardoned, only that this verse does not state what Buchanon says it says.
Ephesians 1:7
In Him we have redemption through His blood, the forgiveness of our trespasses, according to the riches of His grace...
Again: no definition of justification. Instead, Buchanon has moved the goal post. He started out with an intent to define justification but is focusing on the forgiveness or pardon of sins. Justification and forgiveness are not synonymous.
I have gotten into the habit of looking up verses as I read through a book. I am often amazed at how frequently authors take liberty with the text of scripture. More importantly, I am amazed at how willingly I took the matter for granted and assumed what a ThD said about scripture is correctly representative of scripture when that is often not the case. I've considered posting an op comparing various theologians' use of scripture to observe this problem for everyone's edification. I did a comparison of Walvoord and Riddlebarger and found LOTS of problems in this regard. What a verse states and what it is made to say are often two entirely different, often irreconcilable matters. What a verse can be made to say (an exegetic inference) is also often very different than what a verse is made to say (an eisegetic inference). I'm trust Buchanon is a wise man and perhaps that small quote above is not representative of his definition of justification but what was posted is not a definition of justification. It's not a right definition and it's not a wrong definition. It's not a definition. It's a description.
My Corvair is blue with a lowered front end and a convertible instead of the more common hard top. It has four wheels on which I have put white-walled tires.
What is a Corvair? 

Now let's look at the WCF. WCF Chapter 11, Article 1 states the following...
- Those whom God effectually calleth, He also freely justifieth: not by infusing righteousness into them, but by pardoning their sins, and by accounting and accepting their persons as righteous; not for any thing wrought in them, or done by them, but for Christ’s sake alone; not by imputing faith itself, the act of believing, or any other evangelical obedience to them, as their righteousness; but by imputing the obedience and satisfaction of Christ unto them, they receiving and resting on Him and His righteousness by faith; which faith they have not of themselves, it is the gift of God.
We see three things. First the WCF did not define the term, the WCF states the "by of justification (pardon of sins) and, therefore, Buchanon has accurately reflected the WCF. That's good but we still do not have a
definition of justification. We simply understand justification occurs by the pardoning of sins, by accounting and accepting a person as righteous, by the imputation of obedience. Telling you how a biological sample irradiator is made does not tell you what a biological sample irradiator
is.
Q. 32. What benefits do they that are effectually called partake of in this life?
A. They that are effectually called do in this life partake of justification, adoption, and sanctification, and the several benefits which in this life do either accompany or flow from them.
That's not a
definition.
.
It seems the Buchanon's definition is about the same as the Westminster definition (not that that means it's correct). I am in concurrence with the two definitions above.
An examination of the relevant texts proves otherwise.
I'm curious, what is your definition Josheb?
Justification is not complicated. It is a legal term, a term used to label one's ability to stand before a judge and plead his or her case. Soteriologically speaking, no one had any such ability prior to Christ providing that condition. Anyone who might try to stand before God to plead his case would be instantly incinerated because he's a sin-saturated pile of dross desiring only of wrath. In Christ we stand covered in His Son's blood. We, simply put, now have an ability to stand before God and plead our case....... and that case is Christ crucified and resurrected, the propitiation for our sin.
Think of it this way. In the US we have the Supreme Court, and the Supreme Court adjudicates cases relevant to the Constitution. Local courts adjudicate local laws. State courts adjudicate state laws. Appellate courts, similarly, have their domain. SCOTUS will not hear just any case. A case is examined to see if it has justification, to see whether there are any legal bases or grounds for its presentation to SCOTUS. Lacking that justification the case is not heard.
The Greek word, "
dikaioó" means vindication, or acquitted (those two words are not synonymous) and is used as an acknowledgment that justice has been done (which could mean you were guilt
and found guilty = justice done). None of that happens without an ability to stand before the Judge. Pardon, forgiveness, redemption, vindication, and acquittal (and whatever else might be added to that list are not synonymous terms. On the other end of that line of reasoning is the fact scripture is not unnecessarily redundant. If Paul wanted to say "acquitted," then he'd have said acquitted. If he wanted to say, "pardoned," then he'd have said pardoned. He used "justified" because of its sepcific meaning in the context of his writing (which was usually an exposition of the Law in the context of Christ crucified and resurrect.
My regrets, but I have to run out. I'll check back later.