Pierre Marcel on the glory of the covenant of grace. All italics are his.

It is a covenant of grace, that is to say, freely given. It does not depend upon any human condition, it is not a gift in exchange for some service, it does not answer to any fulfillment of law on the part of man. God Himself, in the person of His Son, provides the surety of the covenant, whereby all our obligations are met at the same time as the demands of the divine justice.

Again, it is a covenant of grace, a free covenant, because God by His grace, rendered efficacious by the working of the Holy Spirit, makes man capable of living in conformity with the requirements prescribed by the terms of the covenant. The covenant of grace has its origin in the grace of God, it is put into execution by the grace of God, and it is experienced in the life of sinners through the grace of God. From beginning to end it is pure grace for the sinner. It is God who descends to man and raises him to Himself. It is God who disannuls the covenant of sinful man with Satan and with death (Is. xxviii. 18), who places enmity between man and Satan, who destroys death, and who, taking man for His possession, promises him victory over every adverse power. It is the work of God, only His Work, and all His work. Man cannot lay claim to any personal glory: all the glory emanates from the Father, the Son, and the Holy Spirit.