For by grace are ye saved through faith; and that not of yourselves: it is the gift of God -Ephesians 2:8

We say, “nothing is freer than a gift”. Salvation is so purely, so absolutely a gift of God, that nothing can be more free. God gives it because He chooses to give it, according to that grand text which has made many a man bite his lip in wrath, “I will have mercy on whom I will have mercy, I will have compassion on whom I will have compassion.” You are all guilty and condemned, and the great King pardons whom He wills from among you. This is His royal prerogative. He saves in infinite sovereignty of grace.

When a man pays another his wage, he does what is right; and no one dreams of belauding him for it. But we praise God for salvation because it is not the payment of debt, but the gift of grace. No man enters eternal life on earth, or in heaven, as his due: it is the gift of God. Salvation is the gift of God: that is to say completely so, in opposition to the notion of growth. Salvation is not a natural production from within: it is brought from a foreign zone, and planted within the heart by heavenly hands. Salvation is in its entirety a gift from God. If thou wilt have it, there it is, complete. Wilt thou have it as a perfect gift? “No; I will produce it in my own workshop.” Thou canst not forge a work so rare and costly, upon which even Jesus spent His life’s blood. Here is a garment without seam, woven from the top throughout. It will cover thee and make thee glorious. Wilt thou have it? “No; I will sit at the loom, and I will weave a raiment of my own!” Proud fool that thou art! Thou spinnest cobwebs. Thou weavest a dream. Oh! that thou wouldst freely take what Christ upon the cross declared to be finished. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/3479.cfm