Gen. 15:6 And he believed the LORD, and he counted it to him as righteousness.
In this connection, it is good to take a look at some Greek words which are important for our discussion.
Logizomai and Dikaioo
The Lord counted Abram’s faith as righteousness, not any deed he had done (we will discuss the details of this passage below). Paul argues that this was the case under the Old Testament and likewise now that Christ has been raised. It is important for us to note the concept of imputed/credited righteousness in Romans 4 and elsewhere. The Greek word used in these instances is the verb λογίζομαι (logizomai, G3049), which means “to reckon, count, compute, calculate, count over”[10]. Dr. William D. Mounce says that the “basic meaning of logizomai has to do with counting or thinking”[11]. The important distinction between the Protestant and Roman Catholic doctrine of justification has to do with the fact that the Protestant doctrine of justification declares the sinner to be righteous although he is not fully righteous, because of Christ’s merits. While the Roman Catholic doctrine seeks to make the sinner righteous and only then will he be really justified and righteous. But notice that the word which the apostle Paul uses, logizomai, has to do with counting and thinking of someone as righteous instead of making them righteous (e.g., Rom. 4:3, 4, 5, 6, 8, 9, 10, 11). For all our purposes, as stated at the beginning of this paragraph, justification does not affect our nature or change our inner life; it changes our state from condemned to justified. Robert L. Dabney said:
We believe that the true meaning is not to make righteous in that sense, but only to declare righteous or false righteous in the forensic sense; and that the act of justification does not change the moral state, but only declares, in the forum of heaven, the legal state of the sinner.[12]
Forensic simply means legal. Theologians often speak of “forensic justification” and mean by it as a legal act of God declaring someone righteous.
The same which was true for logizomai is true of the word for justification, δικαιόω (dikaioo, G1344). The word is defined by Thayer as “to render righteous or such he ought to be” and “to declare, pronounce, one to be just, righteous, or such as he ought to be”[10]. Mounce gives it the basic definition of “to declare righteous, justify”[13]. Berkhof says:
This verb means in general “to declare a person to be just. Occasionally it refers to a personal declaration that one’s moral character is in conformity with the law, Matt. 12:37; Luke 7:29; Rom. 3:4. In the Epistles of Paul the soteriological meaning of the term is clearly in the foreground. It is “to declare forensically that the demands of the law as a condition of life are fully satisfied with regard to a person, Acts 13:39; Rom. 5:1,9; 8:30-33; I Cor. 6:11; Gal. 2:16; 3:11. In the case of this word, just as in that of hitsdik, the forensic meaning of the term is proved by the following facts: (a) in many instances it can bear no other sense, Rom. 3:20-28; 4:5-7; 5:1; Gal. 2:16; 3:11; 5:4; (b) it is placed in antithetic relation to “condemnation” in Rom. 8:33,34; (c) equivalent and interchangeable expressions convey a judicial or legal idea, John 3:18; 5:24; Rom. 4:6,7; II Cor. 5:19; and (d) if it does not bear this meaning, there is no distinction between justification and sanctification.[14]
To further elaborat...
