And you He made alive, who were dead in trespasses and sins, in which you once walked according to the course of this world, according to the prince of the power of the air, the spirit who now works in the sons of disobedience. Ephesians 2:1,2
The phrase, course of this world in Greek would read, the aion or age of this kosmos or world, in other words we once walked according to the age or period of time in the earthly or natural, fleshly world. When we are born again we are transformed and translated into a heavenly spiritual realm permeated with God's Spirit. We now walk or exist in this new spiritual life apart from our old fleshly or worldly nature, becoming new creations in Christ.
Before we become Christians we are by nature children of God's wrath and anger destined for eternal judgment to be punished for our sins. When we come to Christ we are saved by His grace, washed in His blood and delivered from the present world system to rule and reign with Him. We are now by adoption children of God destined for eternal glory and ultimately eternal life.
Most people don't understand their position with God before they are saved, they are led to believe that their goodness or good works will eventually allow them access to eternal redemption when in actuality they are going to be cast into pits of darkness and destruction forever because they were never redeemed by the Savior's blood. They are enemies of God deserving eternal punishment because the way of salvation was perverted and distorted by false prophets with evil motives.
That at that time you were without Christ, being aliens from the commonwealth of Israel and strangers from the covenants of promise, having no hope and without God in the world. Ephesians 2:12
In our lost state we are in a hopeless condition of depravity, sinking into a bottomless pit of eternal retribution without God and our minds are darkened to the riches of His eternal plan of salvation for our lives. Once the Holy Spirit begins to enlighten us to His grace we are given a chance to choose His way of salvation and escape eternal judgment. God loved us enough to sacrifice His Son so that His blood could satisfy God's wrath that would be dealt out to all who would reject His mercy.
The world system or present condition of human affairs, in alienation from and opposition to God is the total opposite of His plan for man. The Bible instructs us to be in the world but not to be of it. In other words we are to live in another realm of spiritual life, one far above the fleshly regions of this world. The world system operates in the realm of the five senses and is not accustomed to the things of the Spirit such as faith and communication with another dimension of time and space. Like darkness and light they have no existence together.
Walking in the Spirit consists of allowing the Spirit of God to lead us and guide us through His word and by prayer and communication with Him. By taking authority over fleshly lusts and rejecting the things of the world one can walk in the peace and provision of God's infinite grace and mercy. The Spirit in us longs for the things of God and our fleshly body wants the things of the world thus producing a lifelong conflict or war between the Spirit and the flesh.
I say then: Walk in the Spirit, and you shall not fulfill the lust of the flesh. For the flesh lusts against the Spirit, and the Spirit against the flesh; and these are in opposition to one another, so that you do not do the things that you wish. Galatians 5:16,17
The word walk in this passage of scripture means to keep step with one another in submission of heart to the Holy Spirit and therefore keeping step with Christ. In other words walking together in the Spirit in unity with Christ and one another in the body. Living life by a new and living way, always immersed in the love and careful protection of the Good Shepherd who is mindful of our every need.
There are innumerable riches in our quest to seek the Kingdom of God and to walk with the Lord Jesus in this world. Being a light in a dark place and spreading the good news of His eternal plan of redemption are indeed a challenge for those who would pursue the greatest commission of all. To gather souls into His eternal kingdom is the utmost honor to be bestowed upon anyone that would choose to obey the gospel by giving hope to those without Christ.
The eternal purpose of God is for His body to walk throughout the world as He did, proclaiming the truth, healing the sick, raising the dead and casting out demons to exhibit to a lost world the power and glory of a loving Savior that has given the ultimate sacrifice of His life. His church of blood washed saints, a kingdom of priests ordained of God to change the world by the power of His Holy Spirit, and to reach the lost with His message of mercy shall harvest the world and obtain glory and honor from the Father.
For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, not of works, lest anyone should boast. For we are His workmanship, created in Christ Jesus for good works, which God prepared beforehand that we should walk in them. Ephesians 2:8-10