As for marriage…
Most believe that marriage as an institution will not be found in eternity based on Christ’s words. I tend to agree. The institution of marriage exists for the purpose of providing justice towards all parties involved, especially when people pro-create. Since I question if pro-creation will be necessary in eternity I highly doubt it will be necessary.
However, this doesn’t mean that spouses will not know each other or love one another in eternity. Their intimacy will be much deeper than what we experience here in our present world. Physical intimacy will not be needed because having glorified bodies those hormonal impulses most likely will not exist. Older couples who are incapable of physical intimacy demonstrate a love beyond such needs.
But in a sense…there is marriage in Heaven. There is the marriage between Christ and the Bride. We’ll all exist in an eternal covenantal relationship centered on Jesus and pleasing Him as eternity unfolds.
Some have argued that Christ’s words leave the possibility for marriage. Christ said that in the resurrection they neither marry nor are given in marriage. Those who argue for marriage in eternity state that Christ’s words were meant to indicate that people don’t arrange marriages nor are people given in arranged marriages. Instead, our partners in eternity will be left to our own discretion. Those who never found their soul mate will have an opportunity to do so. Some point to a reference to "offspring" in the New Earth in
Isaiah 65. But the interpretation leaves many questions. I find this interpretation problematic. So I do not advocate for believing it. But... I don't believe it's a major issue if one chooses to. Because the very same God who designed the joys and pleasures of physical intimacy and marriage will have created the New Creation. No doubt something better awaits us.