One thing Earth and Mars have in common is that they both have an atmosphere with oxygen. Additionally, they both have mountains, volcanoes, and canyons on the planets' surfaces. Furthermore, these two planets had water at least once flowing on their surfaces.
One thing that makes Earth and Mars contradict each other is that Earth is larger than Mars by 6,800 kilometers. Mars is only 6,200 kilometers and Earth 13,000 kilometers. Another contrasting detail is their oxygen. While Earth has enough oxygen for living organisms, Mars has very little oxygen for organisms to breath. Yet another contrasting detail is that Earth's surface is two fourths water, Mars has no water. Lastly, Earth does not have dust storms that cover the whole planet. Only Mars has those kinds of dust storms.
As you can see from the details above, there are not much similarities for Earth and Mars, right? But there are differences as well. I have told you some facts, but not all of course. I recommend that you must research more about Earth and Mars so you would see the truth I speak.