No temptation has overtaken you except what is common to mankind. And God is faithful; he will not let you be tempted beyond what you can bear. But when you are tempted, he will also provide a way out so that you can endure it.
1 Corinthians 10:13 NIV
This past week, my son had chickenpox. It was a most uncomfortable experience for him, and for all of us; 'helplessly' watching him go through something he did not understand - excruciating pain all over his body with hard blisters showing up here and there. To make matters worse, the otherwise trusted onlookers (his parents) were admonishing him not to scratch - how else should he deal with the pain, just bear it?!
Of course, we wanted to do better than give seemingly unreasonable advice, but all the information available on the subject point to the reality that the infection will run its course. What was somewhat soothing however is the belief that you can be infected only once in a lifetime, other things considered. Oh, the comfort that gave me! It seemed irrelevant to the emotions and pain of the present moment, but I was relieved that he would not have to go through the experience later, especially since children had that experience in a milder form. In addition to my faith, I could attend to the young man without fear of contracting the virus because I had gained immunity from having dealt with it earlier in my life.
The science of it in simple terms is that the virus, when it has run its course, becomes an antibody which our body systems recognize and use as some sort of vaccine against future threats. This, for me, explains the above scripture as follows:
1) The temptation (uncomfortable situation) which you are confronted with is not the lot of 'bad people', it is 'common to man'.
2) God creates a way TO escape it (KJV); not avoid it, but to have that situation as a medium to make the condition bearable for you.
Please note that you can actually get vaccination for chickenpox (and a good number of infections) way before exposure, and that is a description of grace and its provisions.
The summary is this: God allows us to go through some unpleasantness sometimes and ultimately turns it into a much-needed vaccine for other times later in our lives. On top of that, the comfort you get from your situation becomes a tool of comfort to others who would go through similar situations after you.
2 Corinthians 1:3-4 AMPC
So, do not lose faith, or worry that your immunity is low simply because something unexpected hits you, rather rejoice for God ensures that it ultimately becomes a testimony for you!