If you running a good website then you have a good daily visit, if you have good daily visit then you received many comments on your article and if you received many comments so it's fact many of spammers spam you in a comment. Every time it's not possible to filter comments and publish. Filtration is also not a good solution of spammers ( confirm you are not a spammer ).
How to prevent blog from spam comments:
Your blog is your voice means you are boss and generalist of your own blog, every spamming decrease your reader's interest and also you feel irritation so it's important to keep clean everything. The best way to prevent from spam allow only registered or email verified to make a comment. You can use plugins or discuss.
Allow only registered member can comment on your blog. It helps to increase blog subscriber also.
Your WordPress blog also gives you the option to customize comment option under setting tab as per your need.