Why do Syrian Orthodox churches use only paintings and not sculptures, unlike Catholic churches? I am an Orthodox Christian, and in our church we don't have sculptures unlike Catholic churches in my area. We only have paintings and pictures. 

I don't know if this is because of the bull sculpture demolition story of Moses or some other belief.  Is it mentioned anywhere in the bible that we can or cannot pray in front of sculptures?

I Googled based on the comments and found that it is stated that we should not use idols.  Is what the Catholic church does wrong or against the Bible? How do they justify the use of sculptures.

I am actually trying to find the difference between the praying in front of the idol in Hinduism and Christianity.
I am, in fact a Catholic. I was intrigued by your question and so I decided to do some religious research with my Catechism books. So according to the books: The first commandment forbids the making or the use of statures and pictures only when they promote false worship. An example of this would be using a medal, not to remind us of a saint (Such as St. Maximilian Kolbe) but simply as a good luck charm.  It is right to show respect to the statues and pictures of saints, just as we would show respect of those whom we honor or love on Earth. Just as long as we don't give them the honor that belongs to God alone.

Just in case you're interested in that book it's called The New Saint Joseph Baltimore Catechism