I am not sure of the question. Is it just asking for the meaning or 2 Cor 10:3,4?
Perhaps the NAB gives a clearer translation:
3 For, although we are in the flesh, we do not battle according to the flesh, †
4 for the weapons of our battle are not of flesh but are enormously powerful, capable of destroying fortresses. We destroy arguments
The footnote has:
[3b–6] Paul is involved in combat. The strong military language and imagery are both an assertion of his confidence in the divine power at his disposal and a declaration of war against those who underestimate his resources. The threat is echoed in 2 Cor 13:2–3.
Confraternity of Christian Doctrine. Board of Trustees, Catholic Church. National Conference of Catholic Bishops and United States Catholic Conference, The New American Bible.
Thus Paul says that although we are here on earyth, we are fighting spiritual enemies, with powerful spiritual help.