"Couples who pray together, stay together"
As opposed to couples who don't cultivate a spiritual life that places Jesus at the center - of their affections which in turn informs their attitudes, behaviors and actions. "They devoted themselves to the apostles’ teaching and to the fellowship, to the breaking of bread and to prayer" (Acts 2.42 NIV84).
"Couples who serve together, grow together"
The dynamic which results enables the other to appreciate and appropriately position themselves based on the observation of the gifts, skills and passions of the other - sanctified service. "For even the Son of Man did not come to be served, but to serve, and to give his life as a ransom for many" (MK 10.45 NIV84)
"Good roots produce good fruits"
As Jesus often said, "you have heard it said, but truly I tell you . . ." Affections which make much of Jesus express and display themselves in the same manner as healthy plants bearing fruit. Too often, we chase the fruit without considering the reason or cause behind it. "A good tree cannot bear bad fruit, and a bad tree cannot bear good fruit" (MT 7.18 NIV84).