As thy days, so shall thy strength be. – Deuteronomy 33:25

“I am the vine, you are the branches. He who abides in Me, and I in him, bears much fruit; for without Me you can do nothing.” – John 15:5

This provision is meant to meet weakness. The words carry a tacit hint to us that we have no strength of our own, but have need of strength from above. Our proud hearts need such a hint; for often we poor creatures begin to rely upon ourselves. Although we are weak as water, we get the notion that our own wit, or our own experience, may now suffice us, though once they might not have done so. But our best powers will not suffice us now, any more than in our youth. If we begin to rest in ourselves it will not be long before we find out our folly. The Lord will not let His people depend upon themselves: they may make the attempt, but, as sure as they are His people, He will empty them from vessel to vessel, and make them know that their fullness dwells in Christ, and not in themselves. Remember that, if you have a sense of weakness, you have only a sense of the truth. You are as weak as you think you are; you certainly do not exaggerate your own helplessness. The Saviour has said “Without Me, ye can do nothing”; and that is the full extent of what you can do. The Lord promises you strength, which He would have no need to promise you if you had it naturally apart from Him. But He promises to give it, and therein He assures you that you need it. Come down from your self-esteem: stoop from the notion of your own natural ability: divest yourself of the foolish idea that you can do anything in and of yourself, and come down to the strong for strength, and ask your Lord to fulfill this promise in your experience, “As thy days, so shall thy strength be.”~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2062.cfm

“But you shall receive power when the Holy Spirit has come upon you; and you shall be witnesses to Me in Jerusalem, and in all Judea and Samaria, and to the end of the earth.” -Acts 1:8

With God there is power in the ministry, power in prayer, power in all holy work. We may do a vast deal of work, and yet nothing may come of it; and, on the other hand, we may only be able to do comparatively little, and yet great results may flow therefrom: for results depend not on the quantity of the machinery, but on the presence of the Lord.

Do you not all know persons who are not peculiarly gifted, and yet are eminently useful? You do not remark anything about them that is specially noticeable, and yet their whole career enlists attention by its power. Their words tell, for there is character behind them. A consistent life gives force to a plain testimony…God Himself is at the back of the man who is living for Him. He causes him to speak in His name, so that none of His words fall to the ground. Is it not said of the godly, “His leaf also shall not wither; and whatsoever he doeth shall prosper”? This is so with every church where the Lord abides. His presence makes it a power with its children and adherents, a power with the neighborhood, and a power with the age. Its example, its testimony, its effort tells. God uses it, and therefore it answers its end. The power is with God; but the church is the instrument by which that power exercises itself. He uses a living people for the display of living power, and He gives to them both life and power, more and more abundantly. As we desire power with which to labor for God, we must pray that the God of power will remain in our midst. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2182.cfm

Therefore be imitators of God as dear children. And walk in love, as Christ also has loved us and given Himself for us, an offering and a sacrifice to God for a sweet-smelling aroma. -Ephesians 5:1-2

Where God is present, the preservation of purity will be found. The church is nothing if it is not holy. It is worse-it is a den of thieves. Setting the seal of its pestilent example upon evil living, it becomes the servant of Satan, and the destroyer of souls. Who is to keep the church pure? None but God Himself. If the Lord is there, holiness will abound, and fruits of the Spirit will be seen on all sides; but if the Lord be once withdrawn, then flesh and blood will rule, and gender towards corruption, after its own manner; and the church will become a synagogue of formalists. Pray, my brethren, continually, that the Lord may dwell in our Zion, to maintain us in all holy obedience and purity of life.

Where God is, there is the constant renewal of vitality. A dead church is a reeking Golgotha, a breeding-place of evils, a home of devils. The tombs may be newly whitewashed, but they are none the less open sepulchres, haunts of unclean spirits. A church all alive is a little heaven, the resort of angels, the temple of the Holy Ghost. In some of our churches everybody seems to be a little colder than everybody else. The members are holy icicles. A general frost has paralyzed everybody; and though some are colder than others, yet all are below zero. There are no flowing rills of refreshment, but everything is bound hard and fast with the frost of indifference. Oh, that the Lord would send forth His wind, and melt the glaciers! Oh, that the Spirit of God would chase winter out of every heart and every church! No human power can keep a church from the frostbite which numbs and kills. Except the Lord be there, growth, life, warmth, are all impossible. ~  C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2182.cfm