this is the way
1) First of all open your new Gmail ID.
2) After this click on the Settings button appearing on the right side.
3) Here you will get Forwarding and POP/IMAP option.
4) After clicking on the Forwarding option, you have to enter the ad forwarding address. Note that you have to enter your email ID on which you want to receive mails of other IDs.
5) After entering email id click on Next button and then Proceed option.
6) After clicking on Proceed you will receive an email for verification on the new Gmail ID. Gmail user has to click on Verify Mail.
7) After verification, now come back to the Gmail setting page and refresh the page once again.
8) After this you have to click on Forward copy of incoming email to. Click on Save Changes shown below.
After following all the steps mentioned above, emails from one of your Gmail accounts will automatically be forwarded to the other Gmail account.