No, circumcision is not necessary. The worst part is that the circumcised penis is incapable of feeling the erogenous feelings that come from foreskin movement, because they don't have one. Then, the penis head gets all dried up because it's not inside the foreskin when not in use, and then it's rubbing all over the underwear, so the penis head gets rough. In every sense the penis becomes less and less sexual through circumcision.
In fact in many parts of Africa, that's exactly why they circumcise people! They do it to limit the sexual urges of people. They do it to men and women in some African tribes.
The penis is a complex sexual organ and it needs all of its parts to provide the maximum pleasure that it can provide. Mammals have evolved over millions of years to have the sexual organs that they have and they are designed to give the ultimate in sexual feelings.
Women moan and get wet down in their genitals, and a natural uncircumcised man can also moan and get wet. You just need to learn to discover your own body.
Anyway, circumcision is a sad situation and millions of men in America were circumcised when they were babies and they didn't have a choice. They can't possibly imagine what it's like to have a natural penis, so I would just ignore what they say. There's no point in even talking about it with them either, because they don't have a foreskin.
Just remember to pull back the foreskin and wash the penis once a day. Also wash after ejaculating, because the sperm can be smelly.