Calvin and Luther undoubtedly shared a perspective of a forensic act of justification based on an alien righteousness imputed to believers. Yet while some try to pass off Luther and Calvin as essentially twins on the subject, some differences do remain. These differences are competently exposited by Mark Garcia in his book Life in Christ: Union with Christ and Twofold Grace in Calvin's Theology. Garcia writes:
"Unlike his Lutheran counterparts, Calvin did not ground good works in imputation or justification but in union with Christ. In contradistinction with Melanchthon, for example, Calvin argued a positive, soteric value of good works as the ordinary prerequisite for receiving eternal life. It appears that basic differences exist in their respective understandings of justifying faith: at the heart of the inseparability in Calvin's unio Christi-duplex gratia formulation is a justifying faith defined not only passively, as resting on Christ alone, but actively, as an obedient faith that, resting on Christ alone, perseveres in the pursuit of holiness" (p. 260).
Gracia goes on to note that many in the Reformed tradition (e.g. Charles Hodge) have given sway to the Lutheran view rather than following Calvin when they assert that sanctification is the logically corollary of justification. Garcia states: "Within Calvin's soteriological model, to make sanctification follow justification as an effect is to concede the theological possibility that one may be truly justified but not yet sanctified, with the result that the legal fiction charge, to which Calvin was always sensitive, would be validated" (p. 264). I think on Calvin's model that there is no split nano-second of delay between justification and sanctification as both occur in Christ.
