Yo-yo faith does the exact same thing.
So God has seen you through a tough time. You have felt His love and provision, and you can't stop singing His praises. And then reality kicks in again, you are busy and preoccupied with a thousand things, and before you know it, the singing stops and the high evaporates.
You may say, "That is just because of the crazy time we live in. So many demands, so fast-moving, so hectic, and it gets worse the older I get."
Not so. Robert Robinson wrote a hymn about this in 1757, at the tender age of 22.
Come, Thou fount of every blessing,
Tune my heart to sing Thy grace,
Streams of mercy, never ceasing,
Call for songs of loudest praise,
While the hope of endless glory
Fills my heart with joy and love...
Verse after verse he praises God's grace. And then he throws in this:
Prone to wander, Lord, I feel it,
Prone to leave the God I love.
Here's my heart, oh, take and seal it,
Seal it for Thy courts above.
Yo-yo faith is not an issue of our modern times. It is an issue of our fickle hearts.
The way God takes and seals my heart is by filling it with love for others. No religious fervor, no amount of academic Bible study, not a minute of volunteer hours will tie my heart to Him. They will just keep me busy and feeling good about myself... for a while. Yo-yo faith indeed. Why do you think Christ keeps telling us to love our neighbor, love our brother, love our enemy - and whoever else we can think of, love them too? He doesn't want our hearts on temporary highs followed by periods of deflation and a sense of failure - He can't build His kingdom on so shaky a ground!
Easy as pie, once I figured it out.
For example, I co-lead a weekly women's Bible study. I prep the lesson, I set up the room, I keep the study running and on target. But I know for sure that the only way for my faith to be visible to the group is through my love, not my Bible knowledge, not my personality, not my table runners, not my prayer emails. Are the women in the group in my heart, truly and consistently? If so, I am close to Christ. If not, my heart wanders off and the farther it goes, the quicker I lose all joy and purpose.
The difference between "doing it" and "doing it right" is the love that drives me. I go from "prone to wander" to "here's my heart, o, take and seal it" because of that love and compassion. Christ tells us to love one another not just for the benefit of the one on the receiving end. He tells us to love one another because the very act of caring puts our hearts firmly in His hand; the most solid, unchanging, reliable and save hand there is.
As I said, easy as pie. This doesn't mean that I always get it right. But it certainly means that I know how to change course when I don't.