The initial verse that comes to mind is:
Matthew 11:12 And from the days of John the Baptist until now the kingdom of heaven suffereth violence, and the violent take it by force.
John came preaching repentance and the Kingdom of Heaven as well as Jesus, the apostles, and the early church. This is the very message we should be preaching as well to advance Gods Kingdom against the forces of darkness and hell.
As a result of this preaching sinners who hear the message are apprehending/pressing into the kingdom.
Preaching the Gospel, repentance, and the Kingdom of God is an offensive form of warfare advancing the truth with a violence so to speak. When sinners hear the call they willingly take or receive the truth in the same manner.
Another portion that comes to mind about our warfare in advancing the Kingdom against the gates of hell is:
Ephesians 6:10-18 Finally, my brethren, be strong in the Lord, and in the power of his might. (11) Put on the whole armour of God, that ye may be able to stand against the wiles of the devil. (12) For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places. (13) Wherefore take unto you the whole armour of God, that ye may be able to withstand in the evil day, and having done all, to stand. (14) Stand therefore, having your loins girt about with truth, and having on the breastplate of righteousness; (15) And your feet shod with the preparation of the gospel of peace; (16) Above all, taking the shield of faith, wherewith ye shall be able to quench all the fiery darts of the wicked. (17) And take the helmet of salvation, and the sword of the Spirit, which is the word of God: (18) Praying always with all prayer and supplication in the Spirit, and watching thereunto with all perseverance and supplication for all saints;
In this portion we see both defensive and offensive equipment in the advancement of the Gospel and the Kingdom. Once we put on the whole armor of God we take the offensive by faith using Gods Word preaching the Gospel and most importantly praying in the Spirit. The Holy Spirit is given to empower us to take the armor and advance Gods Kingdom being witnesses for Him and the Gospel.
Luke 4:18-19 The Spirit of the Lord is upon me, because he hath anointed me to preach the gospel to the poor; he hath sent me to heal the brokenhearted, to preach deliverance to the captives, and recovering of sight to the blind, to set at liberty them that are bruised, (19) To preach the acceptable year of the Lord.
The very same anointing and commission that was upon Jesus is also upon His church for Jesus Himself said:
John 14:12-13 Verily, verily, I say unto you, He that believeth on me, the works that I do shall he do also; and greater works than these shall he do; because I go unto my Father. (13) And whatsoever ye shall ask in my name, that will I do, that the Father may be glorified in the Son.
My thoughts.