What is the conflict between Antonio and Shylock? Does it have any roots in religion?

Both Antonio and Shylock have had business dealings in the past. Shylock claims that Antonio has spit on him, called him a dog, and insulted him for lending money for profit.

He hath disgraced me and hindered me half a million, laughed at my losses, mocked at my gains, scorned my nation, thwarted my bargains, cooled my friends, heated mine enemies—and what’s his reason?

Shylock says his famous lines about how a Jew is no different than a Christian,

I am a Jew. Hath not a Jew eyes? Hath not a Jew hands, organs, dimensions, senses, affections, passions?

We can surmise that much of this antagonism is rooted in religion. Antonio feels that Jews are inferior while Shylock feels persecuted by Christians.

The conflict between the two characters is not exclusively based on their religious differences, though. There is an economic conflict that exists between Antonio and Shylock as well. In Act I, Scene 3, Shylock tells audiences the three reasons why he hates Antonio.

1. Antonio lends money without charging interests unlike, Shylock charges interests. Because of it, there is a spoil in his business.

2. Shylock is a Jew and Antonio is a Christian. Jews and Christians have enmity with each other.

3. Antonio sometimes criticises about Shylock sometimes with his friends.

4. Antonio used to insult Shylock by saying unusual words (such as, dog) and behave wrongly with him.