God’s ways work God’s way:
Spirit of God is received by hearing with faith (Gal.3.2);
Spirit of God is supplied by hearing with faith (Gal.3.5);
Spirit of God is received by faith (Gal.3.14);
through the Spirit of God, by faith, we remain focused upon Christ (Gal.5.5);
in this way God sends the Spirit of His Son into our hearts (Gal.4.6);
and it is by this very Spirit we will be made to walk (Gal.5.16),
bearing the fruit of the Spirit (Gal.5.22).
So then, by faith, we both live by and walk by the Spirit (Gal.5.25).
Or, as Paul says elsewhere, it is by faith in Christ that the righteous shall live (Gal.3.11).
Having begun (justification) in the Spirit, we continue (sanctification) in the Spirit, and finish (glorification) in the Spirit (Gal.3.3).
Whereas, the Law (striving by/under it) isn’t of faith (Gal.3.12)!!!