バルナバによる福音書 宗教的テーマ
パウロは割礼のようなユダヤ人の律法を守ることで「ユダヤ人を満足させよう」とした点でペトロを攻撃している。この点でバルナバはペトロに従ってパウロに反対したとされている。このことは当時のガラテヤの住民がパウロの信仰に反対する福音書を用いており、バルナバによる福音書もそのうちの一つだったことを示していると感じる者もいる(が、ペトロの手紙二との兼ね合いでペトロによる福音書の方が彼らの用いていた福音書としてより自然であると考えられる)。ガラテヤ書の説明に対してバルナバによる福音書の導入的な章を比較することができる:
Dearly beloved the great and wonderful God hath during these past days visited us by his prophet Jesus Christ in great mercy of teaching and miracles, by reason whereof many, being deceived of Satan, under presence of piety, are preaching most impious doctrine, calling Jesus son of God, repudiating the circumcision ordained of God for ever, and permitting every unclean meat: among whom also Paul hath been deceived, whereof I speak not without grief; for which cause I am writing that truth which I have seen and heard, in the intercourse that I have had with Jesus, in order that ye may be saved, and not be deceived of Satan and perish in the judgment of God. Therefore beware of every one that preacheth unto you new doctrine contrary to that which I write, that ye may be saved eternally.—Introduction to the Gospel of Barnabas
前の章句から、最初からパウロとバルナバは互いに仲良くしていたのではないかと主張される; しかし最終的には彼らはユダヤ教の律法を重要視するかどうかで別れることになる。
以下の章句によれば、イエスはバルナバに語りかけて秘密を授けた:
Jesus, weeping, said: "O Barnabas, it is necessary that I should reveal to you great secrets, which, after that I shall be departed from the world, you shall reveal to it." Then answered he that writes, weeping, and said: "Suffer me to weep, O master, and other men also, for that we are sinners. And you, that are a holy one and prophet of God, it is not fitting for you to weep so much."

Jesus answered: "Believe me, Barnabas that I cannot weep as much as I ought. For if men had not called me God, I should have seen God here as he will be seen in paradise, and should have been safe not to fear the day of judgment. But God knows that I am innocent, because never have I harboured thought to be held more than a poor slave. No, I tell you that if I had not been called God I should have been carried into paradise when I shall depart from the world, whereas now I shall not go thither until the judgment. Now you see if I have cause to weep.

"Know, O Barnabas, that for this I must have great persecution, and shall be sold by one of my disciples for thirty pieces of money. Whereupon I am sure that he who shall sell me shall be slain in my name, for that God shall take me up from the earth, and shall change the appearance of the traitor so that every one shall believe him to be me; nevertheless, when he dies an evil death, I shall abide in that dishonour for a long time in the world. But when Muhammad shall come, the sacred Messenger of God, that infamy shall be taken away. And this shall God do because I have confessed the truth of the Messiah who shall give me this reward, that I shall be known to be alive and to be a stranger to that death of infamy."—
またバルナバによる福音書によれば、イエスがバルナバに福音書を書くよう促した:
Jesus turned himself to him who writes, and said: "Barnabas, see that by all means you write my gospel concerning all that has happened through my dwelling in the world. And write in a similar manner that which has befallen Judas, in order that the faithful may be undeceived, and every one may believe the truth."—