The issues of understanding what is meant when a biblical writer uses “dia” or “di” are many. The basic idea of “dia” as a preposition is to show movement from one end of something to the other, i.e. to go “through” a tunnel includes entering, traveling along, and exiting the tunnel. So the basic meaning is well translated using “through.” The second usage to express the movement of time, from “throughout” the time, i.e. all of the specified time, or something occurring “within” the time specified. The third usage, with genitive, is to show causality. So rather than indicating something occurred because of something, it actually refers to something happening by the means of something. But if “dia” is used with an accusative, then it should be translated as “because of” but with a genitive it should be translated as by means of. Now here is where it gets tricky, because genitive constructions can be understood in several different ways. For example, are we saved by means of Christ’s faithfulness, i.e. the faith of Christ, or are we saved by means of our faith toward Christ, i.e. faith in Christ? Since both aspects are true, we need to figure out which meaning the biblical writer intended. In this very abbreviated study, lets boil this all down using just one verses, Galatians 2:16.. Here is how the NASB95 renders our verse: “ nevertheless knowing that a man is not justified by the works of the Law but through faith in Christ Jesus, even we have believed in Christ Jesus, so that we may be justified by faith in Christ and not by the works of the Law; since by the works of the Law no flesh will be justified.” Note that the translation indicates the idea that “through faith in Christ Jesus” is our faith toward Christ, i.e. faith in Christ. In this usage, we see that “dia” is followed by three nouns in the genitive case, faith, Jesus and Christ. Many translations render it “through faith in Jesus Christ” but the NET comes down of the side as a subjective genitive, i.e. the faith in view is Christ’s. So if we translate “dia” as “by means of” and then translate as a subjective genitive, we get “by means of Jesus Christ’s faithfulness.” So we are justified by means of the precious blood of Christ rather than by our faith in the precious blood of Christ. But, you might say, the very verse says we are justified “by faith in Christ.” Not if we make a similar translation decision that if the preposition “ek” (out) when used to show source or origin with genitive, i.e. translated as “by,” the phrase could be translated as “by Christ’s faithfulness.” Again the idea is the source of our justification is the precious blood of Christ. When Christ died on the cross, covered with His own blood, He became the propitiation for the whole world, and access to that grace is granted by God crediting our faith in Christ as righteousness. Knowing this even we have believed into Christ.