Therefore, the redeemed of the LORD shall return and come with singing unto Zion; and everlasting joy shall be upon their head: they shall obtain gladness and joy; and sorrow and mourning shall flee away. – Isaiah 51:11

In due time the Lord gathers together the outcasts into His visible Church. As David enrolled a company of men that were in debt and discontented, so does Jesus Christ gather the indebted ones and the malcontents and makes them His soldiers. These are known as the Church militant. Surely as David did great exploits by those Pelethites, Cherethites, Gittites and strange men of foreign extraction whom he gathered to himself, so does Jesus of Nazareth do great things by those great sinners whom He greatly forgives—those hard-hearted ones whom He so strangely changes and makes to be the Old Guard of His army.

Yes, He gathers them into His Church and He gathers them into His work. The outcasts of Israel He uses for His own Glory. And when He has done that, He gathers them into Heaven. What a surprise it must be for any man to find himself in Heaven when he remembers where he once was! The outcast remembers the ale-bench on which he sat and soaked himself in liquor till he degraded himself below the brute beast. And now to be cleansed in the Redeemer’s blood and to sit among the angels—this will be surprising Grace, indeed! “Oh, to think,” one might well say, “that I, who was once in lewd company, polluted and defiled, am now made to wear a crown and sit at the Redeemer’s feet!” When we reach Heaven, Brothers and Sisters, I do not suppose that we shall forget all the past. And sometimes it must burst in upon us as a strangely Divine instance of love that Christ should have brought us there and set us among the peers of His realm! And yet He will do it! ~ C.H. Spurgeon

https://www.blueletterbible.org/comm/spurgeon_charles/sermons/1302.cfm