Peace and Spiritual Combat
[T]he Christian life is a combat, a war without mercy. Saint Paul, in a letter to the Ephesians, invites us to put on the armor of God to fight not again human enemies… but against the cosmic powers of this dark world and the spiritual forces of evil in the heavens (Ephesians 6:10-12) and he details all the pieces of armor that we must put on.
Every Christian must be thoroughly convinced that his spiritual life can in no way be viewed as the quiet unfolding of an inconsequential life without any problems; rather it must be viewed as the scene of a constant and sometimes painful battle, which will not end until death–a struggle against evil, temptation and the sin that is in him. This combat is inevitable, but is to be understood as an extremely positive reality, because, as Saint Catherine of Siena says, “without war there is no peace”; without combat there is no victory. And this combat is, correctly viewed, the place of our purification, of our spiritual growth, where we learn to know ourselves in our weakness and to know God in His infinite mercy. This combat is the definitive place of our transfiguration and glorification.
But if the spiritual combat of a Christian is sometimes rough, it is by no means the hopeless struggle of somebody who battles in blindness and solitude, without any certitude as to the result of this confrontation. Rather, it is the combat of one who struggles with the absolute certitude that the victory is already won, because the Lord is resurrected. Do not weep! Behold the Lion of the tribe of Judah, the Root of David, has been victorious (Revelation 5:5). He does not fight with his own strength, but with that of the Lord, Who says to him, My grace is enough for you, for My power manifests itself in your weakness (2 Corinthians 12:9) and his principal weapon is not a natural firmness of character or human ability, but faith, this total adhesion to Christ which permits him, even in the worst moments, to abandon himself with a blind confidence in the one Who cannot abandon him. I am able to do everything with the help of the One Who gives me strength (Philippians 4:13). Yahweh is my light and my salvation, whom should I fear? (Psalm 27:1).
The Christian fights, then, against sin, with violence sometimes, called as he is to keep fighting to the point of death (Hebrews 12:4), but he fights with a peaceful heart and his struggle is that much more efficacious, because his heart is more peaceful. For, as we have said, it is exactly this interior peace which permits him to fight, not with his own strength, which would be quickly exhausted, but with the strength of God.
Source: Extract from Searching for and Maintaining Peace by Fr. Jacques Philippe