Jennie explains what happened:

Zac and I climbed into bed on a completely  average night two years ago. We were pretty tired. We just laid there looking at the ceiling, with only small firework fantasies of what God might say. Zac took my hand and spoke the simple words we had been processing for the past few months but not yet been ready to say.

God had been opening our eyes to how precious our temporary lives were and how numbly we were moving through them.
We were over it. We were over building our lives. We were over houses and cars and cute Christmas cards. We wanted something; we couldn’t put our finger on it. It was burning in us. We had loved so many other things more than God.
We were ready to do anything.