Fight we must, constantly, without rest. Every child of God is a soldier of Jesus Christ, called as were the Levites of old to war the warfare of the Lord. And every office bearer must know that as he takes office he enters into that warfare.
It is a warfare for God, against Satan. It is a participation in the war which God himself wages against Satan, and which God’s holy angels wage against Satan’s angel-hosts. The war of the world against the King of glory. The war of the spirit against the flesh. War within us and without. War which emanates from God and is directed against the might of Satan, the world, death, sin, deceit, and the lusts of the flesh.
Therefore it is a war of every one who is anointed with the Holy Spirit. He must fight with Christ, for Christ, and under the leadership of Christ.
…It is evident, then, that there can be no true zeal for the church without spiritual warfare against sin.
Zeal for the church, however pious it may appear to be, is abominable hypocrisy if it goes hand in hand with neglect of spiritual warfare against such enemies of God as lying, uncleanness, self-righteousness, cold-heartedness.
Some there are who pretend to be faithful watchmen upon Zion’s walls but harbor such sins in their own hearts, or overlook them in their children and fellow-church members.
They are unfaithful.
For they allow the enemy free play within. They cry out against the danger of the wolf howling outside the walls, while a pack of wolves is busily devouring the sheep within!
This is not real devotion to the cause of Christ. Nor does it reveal true faith.
Dr. Abraham Kuyper in the chapter titled “The Church of Jesus Christ” (and the section headed by “Fighting the Good Fight”), found in The Practice of Godliness, (translated and edited by Marian M. Schoolland; Wm. B. Eerdmans, 1948), 57-58.