Phil George explains that the purpose of marriage isn't only about happiness. Rather, we see from Scripture that the purpose of marriage is to display the glory of God. So often, we focus on the individual person instead of the foundation of marriage, that is Christ and the Gospel.

Genesis 2:24 (NKJV) - "Therefore a man shall leave his father and mother and be joined to his wife, and they shall become one flesh."

So, for a couple that's struggling in their marriage, the thing I would want to do first and foremost is to point them to what the purpose of marriage is. So often today, the purpose seems to be focused upon the couple themselves getting their needs met, having their happiness be what's fulfilled first and foremost. But from scripture what we see is that the purpose of marriage, as in the purpose of all things, is the glory of God. And so if a couple has that mindset, then that helps them have the right foundation on which to focus on. The second thing that I would point them to is the truth and the hope that's found in the gospel.

So often we come to having his needs or her needs or love tanks and air hoses and all those things where the focus is upon the individual person rather than upon the foundation being Christ and the gospel. To have someone recognizing what Christ has done in them and for them and be able to live in light of that in a self-sacrificial way. That's really where the foundation needs to lie.