Had been for were, A.V.; into for in, A.V. Into the name. In seems preferable (comp. Matthew 10:41, Matthew 10:42). The use of the prepositions in the New Testament is much influenced by the Hebrew, through the language of the LXX.
As regards baptism in the Name of the Lord Jesus, here and Acts 8:39, T.R.; Acts 10:48; Acts 19:5, we are not to suppose that any other formula was used than that prescribed by our Lord (Matthew 28:19).
But as baptism was preceded by a confession of faith similar to that in our own Baptismal Service, so it was a true description to speak of baptism as being in the Name of Jesus Christ.