To those of Muslim faith, why do you also use the book of barnabas?

You got the wrong verse, 6:18 is as follows:

18. "He is the irresistible, (watching) from above over His worshippers; and He is the Wise, acquainted with all things."

You are stereotyping..Some Muslims scholars may refer to previous scriptures to try and justify a point.

I do not think that the Gospel of Barnabas is very sound. In fact, it says some anti-Islamic things such that Jesus is not the Messiah. And this is contradictory to the Islam understanding.

Further, I dont know where you got your references from

Surah 6:18

He is the Omnipotent over His slaves, and He is the Wise, the Knower. (18)

For what purpose should we use the Gospel of barbabas?when we have the last divine book the Quran and the teaching of our and your prophet Muhammad pbuh,but i think this book is the nearest to the real divine book of Bible.Allah know the best.

Please don't use the wrong qouting of the verses from the holy Quran,because there is no such surah which you mentioned in your question.

Allah bless and guide us to the straight path.Aameen

who the hell said that??? cause we dont the only books that we go by Is the Quran and the Hadith which the Hadith is from the Prophet (pbuh)