In John (1:12), the writer establishes the quid pro quo of New Testament faith. The KJV says: “But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name.” Many “literal” translations say, “…believe into his name.” Murdock’s translation of the Aramaic Peshitta renders it, “…believe on his name.” The NET Bible translates it, “…believe in his name.”
The Greek version (Textus Receptus) says: “osoi de elabon auton, edoken autois exousian tekna theos genesthai, tois pisteuousin eis to onoma autos,”
The words that give us trouble, it might be expected, are “pistueousin” and “eis to.” Without belaboring the point, I will simply state that “pistueousin” means “being faithful” and not “believing.” But, perhaps more importantly, the Greek preposition "eis" means "for" and is used to indicate the object, aim, or purpose of an action. (see: From faith to faith)The action in this instance is in the verb "being faithful". So, the object, aim, or purpose of being faithful is "eis to onoma autos,” "for [the purpose of] his honor."
A better translation of John 1:12 is:
All those, moreover, who took hold of him, to them he gave the authority to become children of God, those being faithful for his honor.