Why is Eve so vulnerable to the devil's attack?

Genesis 3:3

"...but God did say, 'You must not eat fruit from the tree that is in the middle of the garden, and you must not touch it, or you will die.'"

In the garden, Satan comes to Eve with a probing question: "Did God really say, 'You must not eat from any tree in the garden'?" In her reply to him, Eve reveals how susceptible she is to the devil's attack:

The woman said to the serpent, "We may eat fruit from the trees in the garden, but God did say, 'You must not eat fruit from the tree that is in the middle of the garden, and you must not touch it, or you will die.' "

Eve does two things that we should never do: she adds to the word of God and she subtracts from it. Eve adds to the word of God when she says God told them that they must not touch the tree of the knowledge of good and evil. God did say that they must not eat from that tree, but he never said that they cannot touch it. Secondly, Eve subtracts from the word of God when she says, "you will die." God said, "you will surely die," but Eve takes the absolute out of God's word when she says, "you will die."

The word of God is an essential component of the Christian armor (Ephesians 6:17). It is the sword of the Spirit, which we can use to ward off the devil when he attacks us with his lies. But the word is no longer a sword when we add or subtract to it.

On the importance of reading the Bible carefully and knowing exactly what it says

Genesis 3:1

Now the serpent was more crafty than any of the wild animals the LORD God had made. He said to the woman, "Did God really say, 'You must not eat from any tree in the garden?'"

In the garden, the devil comes to Eve in the form of a serpent and asks, "Did God really say, 'You must not eat from any tree in the garden?'" Here, the devil tries to deliberately change the word of God. In Genesis 2:16 God says the exact opposite of what Satan says. The Lord God said, "You are free to eat from any tree of the garden..."

God proclaims to us in his word that we are free (John 8:36 "So if the Son sets you free, you will be free indeed."), but Satan tries to shackle us by planting in our minds a view of God that is a lie. This is his strategy to get us to fall into sin. And as we read on in this tragic passage (Genesis 3), we find that one of the reasons why Eve is not prepared for this attack is because she does not know exactly what the Bible says.