Repeating keywords within your page is usually (when caught) considered spamming, this as you can imagine could result in heavy penalties.

You could easily avoid your visitors noticing this and avoid being accused of spamming by adding content that is both useful and meaningful, following grammatical sentence structures, This way not only will you not be penalized for spamming, You will have more words that naturally come with your keywords and thus naturally come with the search phrase, and best of all you would be adding value to your visitor !