Let us hold fast the profession of our faith without wavering; (for He is faithful that promised;) – Hebrews 10:23

A true church in her holiness and testimony is very terrible to sinners. The ungodly care not a rush about a mock church, nor about sham Christians; but a really earnest Christian makes the ungodly abashed.

Let us be very earnest to maintain the faith once delivered to the saints. Let us not give up this doctrine or that, at the dictates of policy or fashion; but whatsoever Jesus saith unto us, let us receive it as the word of life. Great injury may be done to a church ere it knows it, if it shall tolerate error here and there; for false doctrine, like the little leaven, soon leavens the whole lump. If the church be taught of the Spirit to know the voice of the Good Shepherd, a stranger it will not follow; for it knows not the voice of strangers. This is part of the education which Christ gives to His people: “All thy people shall be taught of the Lord.” They shall know the truth, and the truth shall make them free. May we, as a church, hold fast the things which we have learned and have been taught of God; and may we be preserved from the philosophies and refinings of these last days. If we give up the things which are verily believed among us we shall lose our power, and the enemy alone will be pleased; but if we maintain them, the maintenance of the old faith, by the Spirit of God, shall make us strong in the Lord and in the power of His might. Wrap the colors round you, ye standard bearers, in the day of danger, and die sooner than give them up. Life is little compared with God’s lovingkindness, and that is the sure heritage of the brave defender of the faith.~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/0984.cfm