If we are His, we are at war, and that affects everything.

The Three Gs, which all - boys and girls, men and women - need to know and study for all our lives, must be understood in their biblical context. They need to be learned in the context of the antithesis. What is antithesis? Such a fancy term has a pretty basic meaning. It's us versus the world. We remember that after Adam and Eve ate of the forbidden fruit, God pronounced a curse on each. But He also cursed the serpent, saying, "Because you have done this, you are cursed more than all cattle, and more than every beast of the field; on your belly you shall go, and you shall eat dust all the days of your life. I wil put enmity between you and the woman, and between your seed and her Seed; He shall bruise your head, and you shall bruise His heel" (Gen. 3:14-15). Here God declares solemn war against the serpent, and not only promises to destroy the serpent through one born of a woman, but also promises to change the hearts of His elect, such that they would hate the serpent. This great battle is the setting of history, and therefore the setting of our lives. If we are His, we are at war, and that affects everything.

R.C. Sproul Jr.
From the book: When you rise up

If we are His, we are at war, and that affects everything.

http://pollys-peak.blogspot.com/2005/12/if-we-are-his-we-are-at-war-and-that.html