The following dialog I had with a hindu online may help.
interfaithdialog.wordpress.com
You have to be more focussed on proving to him that Allah can only be one and that poytheism or pantheism are uttery illogical beleifs.
If your friend thinks...
Assalam 'alaikum all
Please tell me of some bank which is totally interest-free and sharia-compliant where I can open a current account which can be accessed through the internet without any extra charges i.e. once the account has been set up the internet banking facility should be completely...