Today's Scripture reading is Hebrews 4:12, "For the word of God is quick, and powerful, and sharper than any twoedged sword, piercing even to the dividing asunder of soul and spirit, and of the joints and marrow, and is a discerner of the thoughts and intents of the heart."
The nourishment we need to be strong in faith comes from the Word of God.  A malnourished Christian is no match for the devil and his team of principalities and powers.  We need not only to be feasting on the Word of God, but we need to learn how to handle it has a sword.  A Spirit and Word filled Christian will be able to overcome the wiles and ways of Satan.  I am not sure what the percentages are, but I would think most backslidden Christians started the slide by neglecting the Word of God.  It matters not how long your Christian resume is, you need to read and meditate on God's Word everyday.  Satan is determined to cause shame to your Heavenly Father by bringing you down.  He will not let up with his attacks.  The Apostle Paul included the Word of God with our spiritual armour.  Ephesians 6:17, "And take the helmet of salvation, and the sword of the Spirit, which is the word of God:" 
Strong in Faith = Strong in the Word