I've found numerous definitions of "deconstructing" as it pertains to faith.
Rather like the word "Christian," the word deconstruction has no precise practical definition.
Yes, you can locate dictionary definitions; but in practical, every day, experience the word means different things to different people.
The word doesn't scare me. If someone tells me they are in the process of "deconstructing my faith" I'm not going to panic or question their salvation. I'm going to attempt to engage in conversation to determine exactly and precisely what they mean by the term.
Whether they are 14, 40, or 70 it may simply mean they are trying to figure out if they really believe what they say they believe.
And that's more than okay. After all, 2 Corinthians 13.5 reads, "Test yourselves to see if you are in the faith. Examine yourselves. Or do you yourselves not recognize that Jesus Christ is in you?—unless you fail the test."
Granted, it is more fun to examine other people; but the Word admonishes us to examine ourselves...to test ourselves...to see if we are actually born-again.
And if you were raised in a church that, for instance, was dogmatically pre-trib, it is okay to examine whether you believe that. Same with modes of baptism, tongues, security, etc.
The Bereans were not questioning their faith as "they received the word with eagerness and examined the Scriptures daily to see if these things were so." In fact, they were "considered more noble" because they did so.
"Deconstruction," due to being in the news frequently, may cause some people to, for the first time, wonder...wonder if they are truly converted, wonder if what they've been taught is accurate, wonder about much...and that's okay!
By the way, if you are wondering about your relationship with Christ; read First John. The "mission statement" of that short letter is assurance of salvation. (5.11-13)
You can "wonder" about "eternal security," but you need not "wonder" if you are a genuine Christ-follower at the present time.