When Dick Peterson's wife, Elizabeth, was diagnosed with multiple sclerosis, he knew many challenges awaited his family. What he didn't know was just how many lessons he would learn along the way about love and service in the name of Christ. He writes:

The intruder invaded Elizabeth's body, and by extension, mine. Her disease became my disease and made demands on our relationship we were ill-prepared to manage. As she moved from cane to walker to electric scooter and finally to a powered wheelchair, then lost use of her right hand, I had to adjust my life to fit her needs.

Uninvited and unwelcome, this disease now forces us into a kind of sick reality game, leaving no choice but to follow the rules even as they change and become more restrictive …

Every family divvies up chores, fairly or not so fairly. The MS dictates ours and it's not at all fair, but we do have the choice to let it tear us apart or use it to strengthen our marriage bond as we face the adversity together. This reaches deeper than deciding who does what. It reaches to feelings, emotions, and attitudes about what we do, what's done to us, and who we are to ourselves and each other …

We both pray for healing. With our families and our church, we agonize before God for a return to the day when Elizabeth can offer an open handshake instead of a permanently clenched fist, or take a flight of stairs without thought.

But if we only grieve the loss, we miss the gain—that what this disease does to us may also be done for us. Even as the MS steals abilities from Elizabeth's life, a healing grows almost undetected inside. When we talk about this, Elizabeth wonders aloud, "Did it really take this to teach me that my soul is more important to God than my body?"

And I ask, "Is this what Jesus meant when he taught his disciples to serve? When he washed their feet, did he look 2,000 years into the future and see me washing my wife's clothes and helping her onto her shower seat to bathe? Did it really take this to teach me compassion?" …

God's healing can be sneaky. We pray that Elizabeth will resume her old life; he wants her to assume a new life. We long for change on the outside; he desires change on the inside. We pray for what we want; he answers with what he knows we need …

[God] has made me question whom it is I love. When I pray for healing, is it for Elizabeth? Or is it because her healing would make life so much easier for me? I challenge, "Aren't you the God who heals? I love her and I want her well." But in the back of my mind I know I also want her healed for me.

In response to my challenge, Jesus asks me as he asked Peter, "Do you love me more than these?" I think, He wants me to love him more than my wife. So I reply with Peter's words, "Yes, Lord. You know that I love you."

"Tend my lambs," he tells me …

The exposure shames me. Do I love him more than these? This is the love of Matthew 22:37–39 that commands me to love God with all that's within me, with all my heart, soul, and mind, and to love my neighbor—my wife—as I would myself.

Loving what I want for myself isn't even on the list. It's not in me to love like that, except that God has promised that his love "has been poured out within our hearts through the Holy Spirit who was given to us" (Romans 5:5, NASB). God has given me an impossible command, but he has given me the power to obey it.

The intruder still resides in our home, still presents us with new challenges each day, and still teaches us forceful lessons on submission, dependence, service, and a love that endures all things and never fails—even when I fail.

Strange as it may seem, that intruder is beginning to look more and more like a guest.