My mom is 80. And has Alzheimer’s.

Last week, I took my mom on a walk around Santiago Park in Orange County. I held her hand as she pointed out the cars, and the kids, and the animals. Mom was a chatterbox that day.

I don't think she noticed that I was fighting back tears the whole time.

My mom, Sunni, immigrated to the US in 1970 during a nursing shortage. She met my dad, moved to Los Angeles, raised two boys, and sponsored eight family members to start new lives in America. Mom worked two jobs as a labor and delivery nurse, delivered thousands of babies over her career, and eventually retired with scores of friends and fans.

Over the years, we watched Sunni slowly disappear. The long goodbye is a painfully apt description of Alzheimer's.

Today, Mom has forgotten most of her past and the people in her life. Her memories are a confusing jumble of fact and fiction. And yet she generally remains pleasant and engaging. She still plays ping-pong, she enjoys arts and crafts, and she can't help tapping her toe when good music is playing. The disease has taken so much, but it hasn't taken everything. Yet.

Sunni is one of 168 million people on Earth today who are 80 or older. By century's end, the UN projects that number will grow to 947 million. About one in every 11 people will be a super senior.

I pray that God provides a cure for dementia soon. Until then, more and more seniors will suffer through the long goodbye. The wave is just beginning. (And it's one of the reasons I wrote Future-Perfect.)

It's taken a lot of time, but I've finally come to understand the power of presence. Simply being with someone, even though they won't remember your visit. The time still matters. The presence still honors them and God.

Walking this journey with Mom raises hard questions, questions I believe we all need to wrestle with:

• How do we share Jesus with seniors suffering from dementia?

• How do we help them to trust in God daily?

• How do we engage them in Kingdom-building work?