Commenting on the idea of baptism εις Χριτον, Robert Tannehill noted:
The interpretation of this phrase has been
the subject of considerable controversy. Some interpreters feel that it is
necessary to give the εις a local sense, while others see it as an abbreviated form of εις το ονομα, and so as a formula for
transfer for ownership, or as an indication of the constitutive factor for the
nature of the baptismal act or an indication of the goal of this act. The
latter kind of interpretation is insufficient. Any interpretation of baptism εις Χριστον must be able to explain how Paul
can move from this idea to the related idea of baptism εις τον θανατον αυτου, and then interpret this as participation
in Christ’s death, as he does in Rom. 6 3 ff. Baptism εις τον θανατον αυτου, does not simply mean that one
is baptized “in the name of his death” or “for his death” or “with reference to
his death.” Paul explains in vs. 4 that it means that “we were buried with”
Christ and in vs. 5 that “we were united with the form of his death.” This
clearly means that the believer shares in this death, is included in this
death. Baptism εις Χριστον must
be understood in the same way. It means through baptism the believer has come
to share in Christ. Through baptism he has been included in Christ. He has
entered Christ as the corporate person of the new aeon. Thus we should
translate: “We were baptized into Christ
Jesus.” (Robert C. Tannehill, Dying and
Rising with Christ: A Study in Pauline Theology [Eugene, Oreg.: Wipf and
Stock, 1967], 22)
Therefore, water baptism is the instrumental means of our being united
with Christ; it is not a mere symbol.