وَقَالَ ٱلرَّسُولُ يَـٰرَبِّ إِنَّ قَوۡمِى ٱتَّخَذُواْ هَـٰذَا ٱلۡقُرۡءَانَ مَهۡجُورً۬ا
The Messenger has said, O my Lord, indeed my people have taken this Quran as [a thing] abandoned. [Quran, 25:30]
Our Prophet (saws) said this before God against those who had left the Quran.
Scholars say that we abandon the Quran when we cease to:
1. Believe in it,
2. Read it,
3. Understand it,
4. Ponder its verses,
5. Act upon it, or
6. Share it with others.