day no. 16,708: the great army of Christ

"Daily there depart from [the church] some who have fought the fight, kept the faith, earned the crown of righteousness, and who constitute the church triumphant, the church of the firstborn and the spirits of just men made perfect (Heb. 12:23). And daily new members are added to the church on earth, to the militant church here below; they are born in the church itself or are brought in by the work of missions. These two parts of the church belong together. They are the vanguard and rearguard of the great army of Christ.” — Herman Bavinck, The Wonderful Works of God, pp. 502-503

The Church grows when its members have children or when new members are added through conversion. The army of God advances as children are baptized and catechized and nations are evangelized and disciplined. Like an army, we lose some to death, but unlike other armies, we gain many from the enemy. Converts do not merely cease firing on us, but join us in firing back.

Hebrews 12:1-2

Therefore, since we are surrounded by so great a cloud of witnesses, let us also lay aside every weight, and sin which clings so closely, and let us run with endurance the race that is set before us, looking to Jesus, the founder and perfecter of our faith, who for the joy that was set before him endured the cross, despising the shame, and is seated at the right hand of the throne of God.

The Church triumphant cheers on the Church militant. In this they are one. They are fighting the same battle and those who have departed share in the work of warfare here as much as those still fighting share in the peace of paradise above. There is one church and those who have long since departed are enlisted in the same army as those most recently born.

Ephesians 4:4-6

There is one body and one Spirit—just as you were called to the one hope that belongs to your call—one Lord, one faith, one baptism, one God and Father of all, who is over all and through all and in all.