The next two questions Paul raised and answered are forensic or legal in nature. Who will bring any charge (enkalesei, “make a formal accusation in court; press charges”; cf. Acts 19:40; 23:29; 26:2) against those whom God has chosen? Satan is identified as “the accuser” of God’s people (Rev. 12:10; cf. Zech. 3:1). His accusations are valid, because they are based on the believer’s sinfulness and defilement. But Satan’s accusations will be thrown out of court, because it is God who justifies. The Judge Himself declares the accused person righteous on the basis of his faith in Jesus Christ (Rom. 3:24; 5:1). As a result all accusations are dismissed and no one can bring an accusation that will stand.
The related question is, Who is He that condemns? The Greek participle ho katakrinōn can have a future sense, “will condemn,” which seems preferable here. (Cf. katakrima, “condemnation, punishment” in 8:1.) Jesus Christ is God’s appointed Judge (John 5:22, 27; Acts 17:31), so Paul answered this question by stating, Christ Jesus. But Jesus is the very One whom the believer has trusted for salvation. Furthermore, He is the One who died—more than that (lit., “but more”) who was raised to life—who is at the right hand of God (cf. Luke 22:69; Acts 2:33; 5:31; Eph. 1:20; Col. 3:1; Heb. 1:3, 13; 8:1; 10:12; 12:2; 1 Peter 3:22) and is also interceding for us. The Lord Jesus Christ is indeed the Judge, but He is also the One with whom each believer is identified by faith. As a result he is a believer’s Sacrifice for sin (cf. Rom. 5:8; 8:32), his new life (a believer shares in Christ’s resurrection life; 6:4, 8, 11; Eph. 2:5–6; Col. 2:13), his Intercessor (cf. Heb. 7:25; also the Holy Spirit intercedes, Rom. 8:26–27) and his Defense (1 John 2:1). Certainly the Judge will not condemn His own who are in Him by faith! (cf. Rom. 8:1)
Witmer, J. A. (1985). Romans. In J. F. Walvoord & R. B. Zuck (Eds.), The Bible Knowledge Commentary: An Exposition of the Scriptures (Vol. 2, p. 475). Wheaton, IL: Victor Books.