Our bodies have a wonderful defensive system called antibodies. When we get certain diseases, our bodies build antibodies to keep us from getting them again. But there is a sad spiritual application of this principle.

Because of the discovery of antibodies, immunization was developed. It was noticed, for example, that those who had cow pox never got small pox. Thus people were purposely given a form of cow pox and small pox epidemics were eliminated.
At first it was experimental. Jonathan Edwards died from inoculation. Others question all the shots children are required to take in order to attend school. We aren’t debating that here. But the body itself builds antibodies against certain diseases. When I was a child, we all knew we would, at one time or another, get the three big ones: chicken pox, measles, and mumps. Hopefully you would get mumps before puberty, but we didn’t know why at the time. If you got them once, you wouldn’t get them again, normally.
We attend a great church. The Gospel is preached, the Word is presented clearly, and the people are loving and serious. But I look on the children who grow up there with concern. They hear it over and over. While some visiting may be greatly affected by hearing the Word for the first time, the children can sit attentively and tune it out. I have asked them the next day what was the subject or text of the pastor’s message. Often they don’t know. They are tuned out. They are immunized. They could stay like this all their lives unless something or someone stirs them to consider personally and seriously the claims of Christ.
But Christians can do the same. “Another message on giving.” click! “Another message on evangelism.” click! What would be the subject you click off? “I will respond to that message the same way I always have,” we tell ourselves unconsciously. We become immune to a fresh challenge from the Spirit. May God stir us afresh with His Word today, and keep us from tuning out any truth He reveals to us.