Righteousness

Arguments why "faith counted as righteousness":
1. First, at the end of verse 6 (Rom. 4:6), " God counts righteousness apart form works." Faith is not the thing counted as righteousness, but righteousness is the thing counted to us. What is counted to our account here is not faith but righteousness.
2. Second, (Rom. 3:21-22) it is God's righteousness that comes to us through faith. Faith is what unites us to God's righteousness. Faith is not God's righteousness which is imputed (reckoned) to us in our union with Christ.
3. Third, (2 Cor. 5:21) we have a double "imputation; God imputed our sins to Christ and God imputed His righteousness to us.
4. Fourth, (1 Cor. 1:30) says that Christ became for us "righteousness", that we are "in Christ Jesus"; Christ, not faith, is our righteousness.

John Piper, Brothers, We Are Not Professionals, pg. 28-30