Yes, I agree that what is within the heart is very important. In fact the Messiah started with that focus (on "the within") with His "Sermon on the Mount" (
Mt 5:1-12).
But, then in
Mt 7:15-21, He warned that
"the within" is revealed by "the without".
Unless there is
obedience (outward expression) to the Will of Our Father [7 Annual Holydays], such "celebration within" is self-delusion.
Mt 7:20-21:
20 "So then, you will know them by their fruits. 21 "Not everyone who says to Me, 'Lord, Lord,' will enter the kingdom of heaven, but he who does the will of My Father who is in heaven."
The movie "Inception" is a perfect illustration of this point. Leonardo always had to keep his "token" with him so he could always tell the real world from the dream worlds he went into mentally.
In the same way, we must always keep "doing the Will of Our Father" (7 Annual Holydays) as our "tokens" (signs) so we can always tell the truth from self-delusion.