 
If we live by the Spirit, let us also keep in step with the Spirit.
Gal. 5:25 ESV
“To keep in step with the Spirit†(Gal. 5:25 NIV) means being so satisfied in God’s great grace and unfathomable love that we are freed from the idols of self. Walking in the Spirit is preferring God’s will over and against the fleeting, false promises of this life. Eternity is valued higher than the passing pleasures of this life as we are led by the Spirit.
According to the Apostle Paul, walking in the Spirit is to led by the Spirit which is an attitude of yielding to where he is going, listening to the his direction, discerning his will, and obeying his guidance.
When we walk in the Spirit . . .
The Holy Spirit changes our motivation: we yearn for holiness instead of demanding our wants and desires to be met now and always.
The Holy Spirit frees our hearts from the fear of retribution for our sins. In its place, the Spirit gives us hearts that yearn to please our heavenly Father.
The Holy Spirit renews our hearts to prefer and refer everything in our lives to the power of God and his holiness.
The Holy Spirit leads our hearts to obey him. We recognize his Lordship and submit all our hopes, dreams, and desires to his will.
The Holy Spirit empowers our wills to defeat the flesh. The Spirit enables us to say, “yes,” to righteousness and, “no,” to ungodliness.
The great thing that the Holy Spirit reveals is that the supernatural power of God is ours through Jesus Christ, and if we will receive the Holy Spirit He will teach us how to think as well as how to live. Always refer back to the receiving of the Holy Spirit, we receive Him to do His work in us. Just as Jesus glorified God, so the Holy Spirit glorifies Jesus; He makes us written epistles not only in living, but in thinking.
Oswald Chambers, Biblical Ethics (Hants, UK: Marshall, Morgan & Scott, 1996), 97.