If I hold 1 or 2 btc for a long time, It will be surely profitable in the future or not???
nobody knows that
Truly none knows what happens in the future of bitcoin. But if you consider earning right now you can go for a buying the possible.
I think yes he will earn some good money from his collected bitcoin as the price increase of bitcoin till the halving is sure and all of those who have bought some bitcoin will definitely earn with that collected amount.