Matthew 4:10-11 "Get out of here, Satin, " Jesus told him. "For the Scriptures say, 'You must worship the Lord your God and sere only Him." Then the devil went away, and angels came and took care of Jesus.
Jesus had been in the wilderness for 40 days without food. Satin came along and tempted Jesus with three things... each time Jesus said, "For the Scriptures say," and quoted words from God's word. Satin went away!! God sent angels to take care of Jesus. Once Satin even used scripture to tempt Jesus.
Jesus knew God's word!!! Jesus used God's words to defeat Satin. That is why it is so important to know God's word so that we too can defeat Satin! So we know what God means by His word so that Satin can't us it against it by turning it and twisting it to his advantage. We need to know God's word it is our weapon against Satin and it is a powerful weapon... a weapon that can defeat the devil every time. But, only if we know it to use it!!
A very simple example of this is when Satin tries to tell us we are useless.. we can say God's word tells me that I am fearfully and wonderfully made!!" (Psalms 139:14) When we know God word we can win the fight...but we have to know God's word and that part is up to us!!