Therefore, if anyone is in Christ, he is a new creation; old things have passed away; behold, all things have become new. – 2 Corinthians 5:17

Methinks, if a man feels within him a new heart, and rejoices in his new birth; if he sees in others new and holier lives, and rejoices in them; if he listens to the preaching of the gospel, and discovers in it new and better principles, such as the old worn-out world could never have discovered, why, that man is a gracious man. The eye that can see the new nature is an eye that grace has given and newly opened to new light. The heart that can rejoice in the new creation is a heart that is itself renewed, or else it would not comprehend spiritual things, and could not rejoice in them…It is a delightful thing that God should make a tree, and bid it come forth in the springtide with all its budding verdure. It is a far better thing that God should take a poor thorny heart like yours and mine, and transform it till it becomes like the fir-tree or the pine-tree to His praise. It is a charming sight when bulbs, that have slept under ground through the winter, hold up their golden cups to be filled with the glory of the returning sun. But how much better that hearts that have lain dead in trespasses and sins should be moved by the secret touch of the Spirit of God to welcome the Sun of Righteousness, and to rejoice in Him!~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2211.cfm