I replaced the timing belt, now it won't start. on 2008 Kia Rondo

I replaced the timing belt. I lined up the markers on the gears, but after I had everything was put back together the car wont start. The engine will rev but will not turn over. After trying to start it, the air backed up and blew off the air filter. What is wrong, please help!!

Asked by for the 2008 Kia Rondo
sounds like your timing is off recheck timing marks and take out #1 spark plug and crank it over until you get to tdc