Romans 8:2

For the law of the Spirit of life in Christ Jesus hath made me free--rather, "freed me"--referring to the time of his conversion, when first he believed. from the law of sin and death--It is the Holy Ghost who is here called "the Spirit of life," as opening up in the souls of believers a fountain of spiritual life (see on Joh 7:38-39); just as He is called "the Spirit of truth," as "guiding them into all truth" (Joh 16:13), and "the Spirit of counsel and might, the spirit of knowledge and the fear of the Lord" (Isa 11:2), as the inspirer of these qualities. And He is called "the Spirit of life in Christ Jesus," because it is as members of Christ that He takes up His abode in believers, who in consequence of this have one life with their Head. And as the word "law" here has the same meaning as in Rom 7:23, namely, "an inward principle of action, operating with the fixedness and regularity of a law," it thus appears that "the law of the Spirit of life in Christ Jesus" here means, "that new principle of action which the Spirit of Christ has opened up within us--the law of our new being." This "sets us free," as soon as it takes possession of our inner man, "from the law of sin and death" that is, from the enslaving power of that corrupt principle which carries death in its bosom.

— Jamieson-Fausset-Brown Commentary (public domain)