The "world," according to John, is the system that operates irrespective of Jesus' lordship. It may or may not explicitly deny Jesus as Lord; however, for all practical purposes, it ignores Him. The world dominates economics, politics, mass media, sports, entertainment, employment, education, and even many churches.
God's word commands us to "have no love for the world, nor the things that the world affords" (1 Jn 2:15). Even a little love for the world is wrong, for "if anyone loves the world, the Father's love has no place in him, for nothing that the world affords comes from the Father" (1 Jn 2:15-16).
A true Christmas is like a buried treasure or a precious pearl. We must put up for sale all that we have to obtain it (Mt 13:44-46). If we have spent some of our resources by compromising with the world, we won't have enough for Christmas. If we let our Christmas be infiltrated by "the world with its seductions," it will pass away (1 Jn 2:17) and leave us empty to face a cold January and a depressing new year.
By the power of the Spirit, make a clean break with the world, worship "day and night in fasting and prayer," give thanks to God, and "talk about the Child" Jesus (Lk 2:37-38). May we be crucified to the world and the world to us (Gal 6:14).