1. Survive an earthquake together.
2. Spend almost all of five months apart. A long way apart, preferably in separate countries.
3. Communicate sporadically at first, then more regularly by phone, email, and Skype.
4. Face many challenges separately.
5. Get back together.
6. Realize many times a day what a blessing your spouse is and how you could so easily have lost him/her. As a result of this realization, treat each other like the one-of-a-kind creations of God you both are and revel in God's incomprehensible and completely undeserved goodness in letting you be together.
Please note: Some experts have suggested that the first five steps could be omitted and that couples could skip directly to #6, with similar results (and fewer side effects). More research needs to be done on this point.
25 minutes ago