What’s the meaning of walking in the flesh as opposed to walking in the Spirit?
When a person becomes a Christian, God’s Spirit is poured out in his or her heart. From now on that person’s life is directed by the wonderful presence of the Spirit (2 Corinthians 1:22), and sealed for the day of redemption with the Holy Spirit (Ephesians 4:30)! When the Spirit dwells in someone it results in a changed life from the center of that person’s being, his or her heart. No longer being a slave of sin, he or she can now walk in accordance to God’s will!
The works of the flesh
Paul paints a very clear contrast between walking in the flesh and walking in the Spirit in Galatians 5:19-26. The works of the flesh are as follows: sexual immorality, impurity, sensuality, idolatry, sorcery, enmity, strife, jealousy, fits of anger, rivalries, dissensions, divisions, envy, drunkenness, orgies (Galatians 5:19-21). Just take a look around you in society, and you can see that these words, which were written down about 2,000 years ago, are still very relevant and true. Despite being religious, people are still mired in sin and unable to pull themselves out of it. There is only one way: trusting Jesus for one’s salvation and receiving the Holy Spirit who will change you from the inside out.
A Spirit-filled life
The Spirit-filled life looks like this: love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control (Galatians 5:22-23). Instead of sexual immorality, there is self-sacrificing love. Instead of idolatry, God is worshiped as the one true God. Instead of enmity, strife and jealousy, there is peace, patience and kindness. Instead of sensuality and impurity, there is faithfulness and goodness. Instead of fits of anger, there is self-control. There is joy instead of dissension and drunkenness.
God’s act of deliverance
Colossians 1: 13 says: “He [God] has delivered us from the domain of darkness and transferred us to the kingdom of his beloved Son.” The contrast could not be bigger. And notice how this transference took place: not through any redeeming act on the human side, but through God’s act of deliverance. This is the big difference between being religious and trying to live a right life, and being a follower of Christ. Being religious is done in one’s own strength; a follower of Christ is delivered not by his own doing but by God. He is transferred into the Kingdom of light by God, he is indwelled by the Spirit of God and changed into the likeness of the Son of God (Romans 8: 29). It is all God’s doing and it is all focused on God, not on us!
Of course this change of heart takes place gradually. On this earth we will never reach being perfect. The Christian life is like a small tree. When it is watered and taken care of by spending time in the Word, meeting with other believers, and so forth, it can grow bigger and bear more and more fruit. Jesus commands us to remain in Him, to acknowledge Him as the vine and ourselves as the branches. Followers of Jesus do have a responsibility here: to give the Spirit as much room as possible. For it is possible to grieve Him, to deny Him room in your heart (Ephesians 4:30). He does not force Himself on you as the devil is in the habit of doing (1 Peter 5: 8). Open the door of your heart wide open to Him and watch Him at work in your life.