Can a resynchronization be avoided when recovering a wallet in Bitcoin Core? I have tried to restore my wallet by replacing wallet.dat with my file, but the issue is that Bitcoin Core started synchronizing from 8 years again. Can some one help me to avoid this because I frequently format my system. So, is there any way to avoid needing to repeat the synchronization?

I have tried -rescan too but it did not work. :( 
It shows my transaction history but does not show my balance for which I assume the sync needs to finish.
The only way to avoid a full resync is to make sure your backup contains the blockchain as it was when you made the backup; not just your wallet.  

Then the core should only need to update with any more recent transactions.

Here is a good article on the subject:  http://bitzuma.com/posts/moving-the-bitcoin-core-data-directory/

And here it is from the Wiki:  https://en.bitcoin.it/wiki/Data_directory