The effects of abiding by spiritual laws are typically gradual, line upon line. If we miss our morning prayer or skip our daily scripture study, there are consequences. We may not notice any change, but we will be different, ever so slightly. Fortunately we do not lose our testimonies in a day. If we miss another day, the effects are more significant, but we still may not notice any difference. Slowly but surely our testimonies grow or deteriorate based on the extent to which we nourish them. Over time the consequences of what seem to be insignificant choices accumulate, and we become who we now are.
Larry Tucker, "The Human Body: A Gift and a Responsibility", BYU Speeches, May 28, 2013
Brother Tucker's primary message in his talk is how the choices we make to our physical bodies may not have immediate consequences but, rather, little, minute consequences over time.
There are laws divinely developed that every single element must follow and does follow, regardless of whether our own elements agree with them or not. One such law is gravity. What goes up, must come down. Another law is the law of the harvest. We reap what we sow. Laws govern our physical world and laws govern our spiritual world. Many times, those worlds are governed by the same law.
Consequences, positive or negative, to the obedience or disobedience of those laws, are unavoidable. Some are immediate and others are gradual. If we fall off the roof, we will notice the consequences immediately. If we ingest hydrochloric acid, we will notice the consequences immediately. But, if we eat a doughnut, we may not notice any consequences. So, we eat another and nothing noticeable. Then another. After a while, months or years, the consequences become noticeable. Likewise, exercise for a day, we may not notice anything. But over time, as we constantly exercise, we will notice.
The exact same thing happens to us spiritually. Most consequences are not immediately noticeable. As Brother Tucker says, we forget to pray once, we probably won't notice anything. But if we forget again, then again, after a while, those consequences become noticeable. Our testimony is weaker. Our desire for all things gospel is lessened. Until....they are gone altogether.
So, I've mentioned it before, there is no middle ground. We are either getting stronger or getting weaker, physically and spiritually.