Yea, let God be true, but every man a liar; as it is written, That Thou mightest be justified in Thy sayings, and mightest overcome when Thou art judged. – Romans 3:4

We have among us those who are not exposed to persecution, but have to stand against assaults of unbelief. That which believers in past ages have accepted as truth, is not believed in many places nowadays; and so it comes to pass that one brings to us a bit of sceptical science which he has picked up from Huxley or Tyndall; another comes with a criticism that he has found in some of the modern divines, who are the devil’s instruments for spreading infidelity; and a third appears with a vile blasphemy from one of the coarser assailants of religion, and each one demands an immediate answer to his quibble, or his difficulty. Do they really expect that we are to answer, on the spur of the moment, every objection that they are pleased to raise? I confess that I do not believe that one human brain is capable of answering every objection that another human brain could raise against the most obvious truth in the world. Do not try to answer cavillers; but if you do, mind that faith is your weapon. If you take the wooden sword of your own reasoning, you may easily be beaten. Believe for yourself, because God has said it; and speak as the Lord guides you. Fix it in your mind, “This is God’s Book. This is His infallible revelation, and I believe it against every argument that can possibly be urged against it. Let God be true, but every man a liar.” This will be sure defensive ground; but if you get off that rock, you will soon find yourself sinking or staggering. For an offensive weapon, take “the sword of the Spirit, which is the word of God”; and if this does not serve your turn, nothing will. Have a thorough, and entire, and childlike faith in the revelation of the Most High, and you will be made strong in those mental conflicts for which in yourself you are so weak.

Nothing but faith can save the present unbelieving church: nothing but firm faith in the grand old doctrines of grace, and in the ever-living and unchanging God can bring back to the church again a full tide of prosperity, and make her to be the deliverer of the nations for Christ: nothing but faith in the Lord Jesus can save you or me. The Lord give you to believe to the utmost degree, for His name’s sake! Amen. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2209.cfm