“In Him we have redemption through His blood, the forgiveness of our trespasses” (Ephesians 1:7).
Federal Visionists love this verse because they think that in Christ we have the forgiveness of our trespasses. Obviously, Federal Visionists do not understand the first thing about the gospel.
The Reformed faith has always insisted that justification is the heart of the gospel. Justification itself includes the two biggies: the forgiveness of trespasses and the imputation of the righteousness of Christ. Yet, justification is also the key that unlocks all the other graces of the gospel. Once we have been justified, we are redeemed, reconciled, adopted, united to Christ, et al.
Federal Visionists assert that union with Christ is the priority. After we are united to Christ, then we receive the other graces of the gospel. They would even go so far as to say that union with Christ precedes justification. Obviously, this is a utter heresy.
We cannot be united with Christ until our sins are forgiven in justification. This is impossible. We must be justified before we can ever be united with Christ. Thus, technically speaking, we are justified apart from Christ.
Therefore, we would never say that we have forgiveness of our trespasses “in him.” Rather, apart from him we have the forgiveness of our trespasses.