The lust of the flesh . . . is not from the Father, but is from the world
Satan first approached Eve through the channel of the lust of the flesh. He planted a doubt in her mind about the fruit of the tree when he said: "Has God said, 'You shall not eat from any tree of the garden'?" (Genesis 3:1). Eve answered, "God has said, 'You shall not eat from it or touch it'" (verse 3). But Satan had piqued her appetite for the forbidden fruit, and she "saw that the tree was good for food" (verse 6). Yielding to the lust of the flesh contributed to Adam and Eve's downfall.
Satan also challenged Jesus through the channel of the lust of the flesh. Our lord had been fasting for 40 days when Satan tempted Him in the wilderness at the point of His apparent vulnerability: "If You are the Son of God, command that these stones become bread" (Matthew 4:3). Satan is not omniscient, but he's not blind either. He learned about Jesus' apparent vulnerability to physical temptation by watching Him go without food for 40 days. He's watching you too, looking for soft spots of vulnerability in your appetites for food, rest, comfort and sex. Temptation is greatest when hunger, fatigue and loneliness are acute.
The temptation of the lust of the flesh is designed to draw us away from the will of God to serve the flesh (Galatians 5:16, 17). When Satan tempts you through the channel of the lust of the flesh, he will invite you to fulfill your needs in ways that are outside the boundary of God's will. Whenever you feel enticed to meet a legitimate need by acting independently of God, you are being tempted through the lust of the flesh.
When you resist the temptations of the lust of the flesh, you are declaring your dependence on God for your needs. As such you are remaining "in the vine," tapping into the resources Jesus referred to in John 15:5. But when you yield to temptation in this area, your fruitfulness as a Christian will suffer because apart from Christ you can do nothing.
Prayer: You are a strong, fruit vine, Lord, and I will not wither as long as I remain in You. Strengthen me today to resist the temptation to meet my needs apart from You.