In today's modern Islamic world, there exists a variety of different groups all under the name of Islam. No matter how different, it is important that the general rule of the thumb applies, that muslims should adhere to the Quran and the Sunnah. And the best way is to be moderate in any situation/place/time.
Nowadays, we also see groups that are claiming to follow the Sunnah but most of the times do not, some take the Sunnah lightly as though it has no value and others, worse.. writing off the Sunnah all at once.
We should be aware of these anti-sunnah/pro-liberal groups and avoid being influenced by their creed and understanding of Islam.
Here's an article by Harun Yahya on why we should follow the Sunnah..
As Allah has revealed in this verse:
Today I have perfected your religion for you and completed My blessing upon you, and I'm pleased with Islam as a religion for you. (Al-Ma'idah 5:3)
Islam is the final divine religion. Prophet Muhammad (peace be upon him) is the Messenger of Allah and the Seal of the Prophets. Al-Ahzab 33:40. The faithful learn the kind of moral values they need to imbibe and observe in order to attain the approval, mercy, and Paradise of Allah; what they must avoid and what they must abide by; what is lawful and what is forbidden; in short, all the details regarding the kind of life that will be pleasing to Allah from the Qur'an. Another mercy and blessing of our Lord for the believers is the Sunnah of the Prophet (peace be upon him).
The Prophet is a blessed individual, whom Allah has sent as a role model for all people with his moral values:
You have an excellent model in the Messenger of Allah for all who put their hope in Allah and the Last Day and remember Allah much. (Al-Ahzab 33:21)
The Prophet is a role model for everyone embracing the Islamic faith, knowledge, and superior moral values. With his patience, trust in Allah, courage, devotion, closeness to Allah, justice, compassion, love, affection for believers, and foresight, he possessed moral values that are greatly admired by the faithful. All believers strongly desire and strive to possess these qualities to attain the moral model required by the Qur'an. For all there reasons, all his words, decisions, recommendations, advice, and life -the Sunnah- represent a most valuable guide for all those who wish to understand and live by the Qur'an.
Many verses of the Qur'an emphasize the importance of obeying the Prophet and adhering to his path. One of these reads:
Whoever obeys the Messenger has obeyed Allah. If anyone turns away, We did not send you [Muhammad] to them as their keeper. (An-Nisaa' 4:80)
What devout believers must do is to adhere to the path of the Prophet and to take his Sunnah as their guide, knowing that he has called them to a path that will give them a blissful eternal life. Those who wish to attain the mercy and Paradise of Allah must, metaphorically speaking, build their house on solid foundations right from the outset.
Anyone who acts out of fear of Allah and strives to gain His approval is a loyal follower of the Prophet and seeks to resemble him in faith and moral values. This, however, is only possible through adhering to the Qur'an and never departing from the Sunnah.
And Allah s.w.t knows best.