What is the experience of Naam?
We can say, the experience of Naam, is the experience of Wahiguru, Himself.
In the beginning of Mool Mantar, Sachay Patshah says:
Ik Oankar Sat-Nam.
Which means, there is only one Lord, which is Naam, and that Naam is Sat, means Truth.
Now when Guru Jee says that, that Naam is Truth or Sat, means it is everlasting, it is eternal, it does not change.
Further on in the Bani, reffering to that Naam,we come to know, that it is : Aad Sach, Jugad Sach, hae bhee Sach, Nanak hosee bhee Sach.
Means, it has been so, changeless right from the very beginning, it has been unchanged throughout all the jugaas, and it shall remain changeless also, in the future eras.
The bani also says: Ekas bin sabh dandh hae. Means, apart from that Naam, everything else is false, means, it has a start and also an end. All devis, devtays, celestial beings, neither world beings, absolutely everything ends in grand dissolution/maha parlay.
Only Naam, only Wahiguru Akal Purukh, only that Shabad, is Sach/Sat. and it is to that primal power, so to say, our Guru Sahiban direct our attention, to which, we should devote ourselves and none other.
For when we devote ourselves to Naam with its Simran, it is only then, when we shall become mindless, karmaless, and merge our surtee in that Naam/Satnam.
That is why the Bani clearly says: Jin Har japeeya, se Har hoeeya.This is Gurmat.
Anything else apart from it, as per means to become one with Him, is manmat
Sat Sree Akal.