A few quick thoughts on Genesis 3:1.
I just noticed tonight what immediately precedes the devil's appearance: the first marriage and the institution of the home. Satan has always been the enemy of the home, and he moves to destroy the first one as soon as it's created.
Note also, "Now the serpent..." The serpent is doing NOW what he's always done--trying to destroy homes, using the same tactics now as then (see Eph. 6:11; 1 Tim. 2:14; 1 Peter 3:7). So I don't think I'm erring to say that every Christian couple should expect opposition and not give place to the devil (Eph. 4:26-27). In the Pauline passages I've cited, our apostle gives us two major ways to avoid giving place to Satan:
(1) men, be the spiritual leaders in your homes and women, quietly follow them (1 Tim. 2:11-15)--Adam and Eve blew it on both accounts, when she led and he followed;
(2) don't go to bed mad at each other--you are asking for it if you do; make up so you don't get bitter (Heb. 12:15) and BREAK up.
God be merciful to our homes!