The flesh is set against the Holy Spirit.
17 For the flesh sets its desire against the Spirit, and the Spirit against the flesh; for these are in opposition to one another, so that you may not do the things that you please.
The world opposes the Father.
1 JOHN 2:15-17
15 Do not love the world nor the things in the world. If anyone loves the world, the love of the Father is not in him. 16 For all that is in the world, the lust of the flesh and the lust of the eyes and the boastful pride of life, is not from the Father, but is from the world. 17 The world is passing away, and also its lusts; but the one who does the will of God lives forever.
And Satan contends with Christ.
1 JOHN 3:8
8 the one who practices sin is of the devil; for the devil has sinned from the beginning. The Son of God appeared for this purpose, to destroy the works of the devil.
We thus see that the flesh is overcome by walking after the Holy Spirit; the world is overcome by loving the Father; and Satan is overcome by believing in Christ.