Someone having their own opinions and deities is great! I've met people who have had their life changed due to their state of mind being altered for the better when they started following a religion.
The only issue I have is when people try and force their opinion on you. It's like someone forcing you to eat Marmite until you like it(or dislike it)
Also, don't confuse expression of opinion with forcing an opinion.
"I love Marmite, Do you?" Is different from "I love Marmite, Why don't you?"