Divorce is not God's will.
God's will in marriage is for mutual grace-filled submission to each other and love&forgiveness. Even where there is adultery, although divorce is permitted, God's will is to see genuine contrition & behavior change, forgiveness and reconciliation.
Why? Because marriage is meant to reflect God's unfailing love for his people. In the same way that God's love never fails, our love for our spouse in marriage should not fail - and love is not a feeling, but an action.
Hosea's marriage to a prostitute was intended to show God's faithfulness to his people during the worst of their unfaithfulness.
In the same vein, however, separation is God's will (I.e. in an abusive relationship). The ideal would be for separation to lead to heart change and reconciliation, but sometimes it does not.
Remarriage is a difficult topic. "Desertion" in 1cor7 could be given a broad application "if they depart you are under no obligation. God has called us to peace". "Desertion" and "peace" extend some liberty to the believer, but all of that must be grounded in texts like "I the Lord hate divorce" (Malachi 2:16) and this one.
Ultimately, it is God's will that our relationships be full of love, grace and mercy - grounded in the understanding that the same is the basis of God's personal relationship with us. How we love our spouses should be a reflection of how God loves us.
