It is said in the Gita, “मामेकं शरणं व्रज”, (Mamekam Sharanam Vraj). It means, “Surrender to Me.” Who is saying this? Supreme Brahma Purņatam Purushottam Brahma Shri Krishna. And Who is He saying it to? To Arjun. And why is He saying it to Arjun? To make Arjun submit, to make Arjun surrender to Him.
Now you go on repeating “Mamekam Sharanam Vraj”. Who are you saying this to? Who are you saying this to? Oh, but we're just reciting it. But why are you reciting it? Are you out of your mind? Shri Krishna just didn't say this like in a state of madness - absolutely not! These teachings of Shri Krishna were to inspire Arjun to surrender to Him. So Whom are we saying it to? Who are we telling or saying to surrender to us? “Mamekam Sharanam Vraj” means surrender to Me. If we mouth these words, these sanskrit words from the Bhagavad Gita, who are we telling to surrender to us?
So the point is that we just mouth or repeat these verses verbally. That's all we do. But we must remember that writing or reading is absolutely 100% useless until and unless we make an effort, and endeavor to practically apply the teachings and, in fact, practice the teachings of the Bhagavad Gita.
