Although the grammatical construction of this verse is difficult, its purpose is clearly to validate what Paul has said in the previous verse. The first part is literally “for if we have grown together in the likeness of his death.” Modern English translations supply with him, to be taken with the verb “have grown together.” And most modern English translations (with the exception of An American Translation* and Moffatt) understand “have grown together” as a means of indicating unity with him. So the Good News Translation translates for if we became one with him; the New English Bible “for if we have become incorporate with him”; and the Jerusalem Bible “if in union with Christ.” The Good News Translation transforms Paul’s noun phrase “in the likeness of his death” into a verbal expression in dying as he did (see Jerusalem Bible “we have imitated his death”). The contrast in the verb tenses (see also v. 8) is significant. Death is viewed as a past experience and the resurrection as a future experience; this is the same contrast between the past and future that was constantly maintained throughout chapter 5.
Became one with him is not easy to translate in some languages. There may be some such expression as “identify ourselves with him,” but more frequently one must employ a more metaphorical expression: “to join up with him,” “to share together with him,” “to become close companions with him,” or “to become just as though we were one person with him.”
In dying as he did is an expression of means—for example, “by dying as he did.” Similarly, by being raised to life as he was is also an expression of means, but in this instance God is the agent—for example, “by God causing us to live again even as he caused Christ to live again.”
Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on Paul’s Letter to the Romans. (UBS Handbook Series). New York: UBS, 1973. For this and other handbooks for translators see here .
