10 Finally, be strong in the Lord and in the strength of His might. 11 Put on the full armor of God, so that you will be able to stand firm against the schemes of the devil. 12 For our struggle is not against flesh and blood, but against the rulers, against the powers, against the world forces of this darkness, against the spiritual forces of wickedness in the heavenly places. Ephesians 6:10-12 (NASB)
There is a great deal more going on in the spiritual than those of us in the temporal know about. All in Christ who still live and breathe are in the world, but are not part of it. Some, of course, live as if they are part of it, but we are called to be separate from the fleshpot world while being filled with the Spirit. Why? Of course if we are in love with this world, this present age, we will become encumbered and distracted from what we should be doing. Also, the world system, its things and its ways are all controlled by our enemy and his rulers, authorities, cosmic powers who do all they can to keep people blind in this present darkness. When believers are temporally focused they are being influenced by evil, if not controlled by it.