How do we walk by the Spirit?
To walk by the Spirit we must acknowledge that the Holy Spirit abides in our human spirit and we must have the desire to obey His guidance/leading (Romans 8:16).
As we acknowledge His presence, the Holy Spirit illuminates our mind as we fellowship with Him (Ephesians 1:18)
It is important to know that we walk by the Spirit through our mind as the scripture confirms that those who live according to the flesh set their minds on the things of the flesh, but those who live according to the Spirit, set their minds on the things of the Spirit (Romans 8:5).
Also, we walk by the Spirit by being a doer of the Word of God, and not hearers only, deceiving ourselves (James 1:22). To be a doer of the Word, it is essential we speak or confess our faith. The scripture confirms that with the heart one believes unto righteousness, and with the mouth confession is made unto salvation (Romans 10:8).
When we confess the Word of God with our mouth, our soul (mind) is renewed which causes our behaviour to be shaped according to the Word of God.