Find such a reputable scholarly opinion, and present it, and it will be integrated into the article. You can't just invent an opposing opinion and expect that it be presented in an article with equal weight. "Islam is peace" is a well studied aspect of Islam. We can't just say "but some scholars assert that Islam is war" - it's not true, and even if there were some WP:FRINGE source making such a claim, we don't put WP:UNDUE weight on it.