What I'm saying is, OK, some of they may not have a really discipled and all-in relationship with Jesus (too many do not!) but some of them may just be dubious about what you mean by the term. They may think you mean some form of individualistic spiritual Lone Ranger-ism, i.e. the notion that you can be in Christ without being a member of His Body.
If you wittingly or unwittingly give them that impression, then right, you are speaking another language, and their eyes do just glaze over.
There's a little Catholic children's prayer book --- with sky of Italian blue on the cover, with the Good Shepherd carrying a little lamb in His arms, "close to His heart" --- called "Jesus and I". In my little papist sprout days, all the little Catholics received these when we were seen years old or so. It gently inculcated personal prayer and a child's sense of belonging to Him and being carried by Him and wanting Him to know all your secrets because He is your good Lord, rescuer from wolves and everlasting Friend.
And of course we learned to pray from our mothers and fathers at mealtime and bedtime, at least. And when praying for Him to make you a good little girl.
It doesn't always result in a mature faith later on. But it's always there, the ongoing invitation to let Jesus lift you up and give you that peace.
If you are a believer you ARE a member of the body of Christ. Joining an organization does not make you a member of the body of Christ. Trusting in Him alone does.