Paul now develops the only solution available for the Christian to stymie the effects of sin and live victoriously. He begins by stating that there is therefore now no condemnation [katakrima] to those who are in Christ Jesus who walk rightly. Most interpret no condemnation to refer to deliverance from eternal judgment. But as we saw in 5:16, 18, katakrima refers to slavery to sin. Thus it refers to freedom from the enslaving power of sin in the life of a believer. This is what the second part of 8:1 explains.
Believers are free from slavery to sin in their experience, if they do not walk according to the flesh, but according to the Spirit. Although this statement does not appear in the two early Greek manuscripts, it does appear in two other early manuscripts and in the majority of NT manuscripts. The inclusion of the phrase in 8:4 also supports its presence here.
The term walk [peripateō] is a unique Pauline term that refers to conduct of life (cf. 4:12; 6:4; 8:4; 13:13). While believers are no longer slaves of sin in their position (5:16, 18; 6:18), only believers who do not live according to the flesh, but according to the Spirit will not experience slavery to sin (cf. 8:13; 1 Cor 3:3).
By René A. López. Excerpted from The Grace New Testament Commentary, ed. Robert N. Wilkin (Denton, TX: Grace Evangelical Society, 2010), 661–662.