The Koran in section "23:86" says "Never has God begotten a son, nor is there any other god besides Him. Were this otherwise, each god would govern his own creation, each holding himself above the other. Exalted be God above their falsehoods!"
Now I could go on but, this section of The Koran, clearly tells me that Jesus isn't the "Begotten Son of God." Now if they are right, we are worshiping a "Jesus" that doesn't exist. So, are we "Christians" worshiping the same God? I say NO.