So then faith cometh by hearing, and hearing by the word of God. – Romans 10:17

Do not try to conquer sin in others, or capture a heart for Jesus, except with the sword of the Spirit. How the devil laughs when we try to make converts apart from Holy Scripture and the Holy Spirit! He laughs, I say; for he derides our folly. What can you do, you children, playing with your little wooden swords-what can you do against men covered from head to foot with the steel mail of the habit of sin? Sunday-school teachers, teach your children more and more the pure Word of God; and preachers, do not try to be original, but be content to take of the things of Christ, and show them to the people; for that is what the Holy Ghost Himself does; and you will be wise to use His method and His sword. No sinner around you will be saved except by the knowledge of the great truths contained in the Word of God. No man will ever be brought to repentance, to faith, and to life in Christ, apart from the constant application of the truth through the Spirit. I hear great shouting, great noises everywhere, about great things that are going to be done: let us see them. The whole world is going to be embraced within the church; so they say. I fear the world will not be much the better for inclusion in such a church. Big boasters should heed the word of the wise man, “Let not him that girdeth on his harness boast himself as he that putteth it off.” If the champion goeth forth with any other sword than the Word of God, he had better not boast at all; for he will come back with his sword broken, his shield cast away, and himself grimy with dishonor. Defeat awaits that man who forsakes the Word of the Lord. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2201.cfm