You need to be able to convince others that the only way to defeat the Devil is in the Bible, which is the word of the Living God. To prove this, we must know the scriptures which confirm that there can be no doubts about the Biblical words being that of God.
1. Isaiah 40:8 The grass withereth, the flower fadeth: but the word of our God shall stand forever.
2. Hebrews 4:12 For the word of God is quick, and powerful, and sharper than any two-edged sword, piercing even to the dividing asunder of soul and spirit, and the joints and marrow, and is a discerner of the thoughts and intents of the heart.
3.2 Timothy 3:16 All Scripture is, given by inspiration of God and is profitable for doctrine, for reproof, for correction, for instruction in righteousness.
4. John 10:35 If he called them gods, unto whom the word of God came, and the scripture cannot be, broken.
5. Matthew 7:24 Therefore whosoever heareth these sayings of mine, and doeth them, I will liken him unto a wise man, which built his house upon a rock.
6. Psalm 119:130 The entrance of thy words giveth light; it giveth understanding unto the simple
7. Psalm 33:4 For the word of the Lord is right, and all his works are, done in truth.
8. John 7:38 He that believeth on me, as the scripture hath said, out of his belly shall flow rivers of living water.
9. Proverbs 2:6 For the Lord giveth wisdom: out of his mouth cometh knowledge and understanding.
10. Luke 21:33 Heaven and earth shall pass away: but my words shall not pass away.
These ten scriptures outlined above should allow you to understand that humankind could not make up those sayings they had to come from Almighty God. Let us cast any doubts aside and recognise that we can only live by the words of God and not what the false words the Devil want you to follow. The Devil is a liar, and God already told you.