Ephesians 6:17-18

Ephesians 6:17 And receive the helmet of salvation and the sword of the Spirit, which Spirit is the word of God,

Ephesians 6:18 By means of all prayer and petition, praying at every time in spirit and watching unto this in all perseverance and petition concerning all the saints,

According to these verses, the way to fight is to take the word of God by all means of prayer. We should not simply have one way of prayer but every means of prayer, exercising our spirit to pray in various ways to take the word of God. It is of no avail to fight against the enemy with our own thoughts and words. we cannot use our mind or utterance to do battle against him. The most effective way to to war against the enemy is to pray-read the word, and the best portion of the word to pray-read is the book of Ephesians.