Fesko on the issue of 'merit'

First, we must demythologize a term. As much as some might consider merit a theological slur, it simply denotes the concept of equity – the idea that if someone meets stated obligations of an agreement then he is entitled to the consequent goal or reward. A number of Reformed confessions employ the term in this manner.¹³⁵ Simply invoking the term merit does not automatically commit one to a specific theological position as evident by the fact that Roman Catholic and Protestant theologians have historically spoken both of merit within their respective theological systems. Where a theologian places merit, who specifically earns it, and how it is defined, on the other hand, is another matter entirely.

[Footnote 135: WCF XVI.v, XVII.ii, WLC qq. 55, 174, 193; Belgic Conf., §XXII-XXIV, XXXV]

(John V. Fesko, The Trinity and the Covenant of Redemption, 303)