Comparing, different mythologies in the world, we can see that everything regardless of their origin share a common idea.

Now, let's analyze this topic further.

The Greek mythology has a lot common with the Vedic (or generally known as the Hindu) mythology. For instance, Olympus is the home of the Greek gods, much like Amravati of the Hindu 'devas' (or literally heavenly beings according to the Hindu tradition).

Zeus, leader of the Olympians, wields a thunderbolt like Indra, Hindu god of war and monsoon. Zeus also rides an eagle like Vishnu, one of the most important Hindu gods, often regarded as the protector of universe.

The feats of the Greek hero, Heracles, known to Romans as the mighty Hercules, reminded many scholars of Krishna, as does his name – 'Hari-Kula-Esha' or the lord of the 'Hari' clan.

The Greek epic of a husband sailing across the sea to bring his wife, Helen back from Troy is strikingly similar to the Hindu epic of Rama rescuing his beloved Sita from Lanka.

In the creation stories of Orphic traditions, a lot of importance is given to Eros, the god of love. Scholars have linked this to Vedic hymns that refer to 'Kama' or desire as the origin of things, which takes people out of void and darkness.

(Referred from 'Olympus' by Devdutt Patnaik)

Just like this connection between Greek and Vedic mythology, there is also a connection between 'The Holy Bible' and 'The Holy Quran'.

One example is 'Saul and Gideon'. In the Bible, Gideon ad Saul are military leaders of Israel between the Exodus and Exile. We see in the book of Judges in the Bible; Gideon is hesitant about leading the Hebrews in battle. God shows his power when he tells Gideon to observe when the troops reach a river, telling them that whoever drinks without His hands Gideon has to send home. The Hebrews have a later victory. In the Qur'an, the same event happens to Saul when he is on the way to meet Goliath. In the Biblical account of Saul and Goliath, Saul is also hesitant about the battle with Goliath's army.

The Quran and the Bible have over 50 people in common. The angel Gabriel is a very important character in both the Bible and the Quran. In the Bible, the angel Gabriel appears and explains the visions of the prophet Daniel, and also New Testament where he appears to Zechariah, telling him of his son-to-be John the Baptist. According to Muslim belief, the angel Gabriel appeared to Muhammad in a cave near Mecca, reciting to him the first verses of the Quran. But Gabriel is not the only character that shows up in both the Quran and the Bible. Both holy books include: Adam, Abraham, Noah, Lot, Isaac, Ishmael, Jacob, Joseph, Moses, David and Goliath, Jonah, Mary and John the Baptist in addition to others, including Jesus.

While Jesus is recognized as the Son of God in the Bible, Muslims believe that Jesus was a prophet who was given a special message, or gospel, to convey to all people.

The Quran mentions Jesus, or Isa, 25 times, but differently each time. The Quran explains that Jesus was born of the virgin Mary. This is why he is called 'Isa ibn Maryam', which means 'Jesus son of Mary'. The Quran also refers to Jesus as 'ruh min Allah', which means 'Spirit from God', 'mushia bi'l Baraka', which means 'the Messiah – someone blessed by God' and 'rasul', which means 'Prophet-Messenger' of God.

The Bible and the Quran both command and restrict violence in protection of their religious communities.

In the Bible, extreme warfare is commanded in order to establish the Jewish religious community in Israel, but then also commands that non-Jews be free to live in Israel unharmed. The Quran also commands warfare to protect the early Islamic community in Arabia, but also limits warfare to those who break treaties or persecute Muslims.

However, one thing that does separate the New Testament from the Quran is that Jesus commands non-violent resistance and love of enemies, even at times when the individual or religious community is threatened, 'a principle that many of his followers neglected'.

(Referred from www.beliefnet.com)

These above depictions of beliefs are just a few to mention. There are many other facts that can be included here, considering the point that there are not just 3-4 religions or mythologies. There are many including Egyptian mythology, Judaism, Zoroastrianism, Buddhism and also other extinct mythologies, just to name a few.

All the religions and mythologies in the world are the feathers of the same bird. Every religion belongs to every man.

The message of Lord Krishna i.e., Bhagavat Gita is for the entire world. The message of Jesus i.e., Bible is for the entire world. The message of Mohammed is for the entire world. So, there is no need of conversion of religions.

The spiritualism must be built up by the preaching of Lord Krishna, Jesus, Mohammed, Buddha, Mahavir etc. Spiritualism means truth like science.

As the Science is the universal subject, spiritualism must also be an universal subject.

'Hijabs', 'Sunday clothes', 'Yamika', 'Kufi', 'Turban', the 'Janeu' (often termed as the sacred thread of Hindu Brahmans), etc; all have the same mission beneath. We all trying to get to where the suffering ends.

At the end of the day, regardless of our beliefs, we all are the same kind: human.

The bigger picture of these religions and mythologies is that they promote 'peace'.

Thus 'peace' is actually in a true sense the most common idea or common thought, that is prevailing in all these epics, mythologies and other holy texts.