It’s absolutely necessary that you know your bible. One reason being that thoughts and voices in your head may try to get you off course. But when Your rooted, and grounded, established, and firm in the word, you can counter those thoughts with a one two punch of the word, and away they will go.
Matthew 4:3-11
3 The devil came tempting Him and said, “If You are the Son of God, tell these stones to be made into bread.” 4 But Jesus said, “It is written, ‘Man is not to live on bread only. Man is to live by every word that God speaks.’”
5 Then the devil took Jesus up to Jerusalem, the holy city. He had Jesus stand on the highest part of the house of God. 6 The devil said to Him, “If You are the Son of God, throw Yourself down. It is written, ‘He has told His angels to look after You. In their hands they will hold You up. Then Your foot will not hit against a stone.’” 7 Jesus said to the devil, “It is written also, ‘You must not tempt the Lord your God.’”
8 Again the devil took Jesus to a very high mountain. He had Jesus look at all the nations of the world to see how great they were. 9 He said to Jesus, “I will give You all these nations if You will get down at my feet and worship me.” 10 Jesus said to the devil, “Get away, Satan. It is written, ‘You must worship the Lord your God. You must obey Him only.’” 11 Then the devil went away from Jesus. Angels came and cared for Him.