Not hard at all friend, but quite different from the current theology of "I can do whatever I want because I'm saved." I suggest that you read MacArthurs "The Gospel According to Jesus" for a thorough and better explanation.
And who preaches that?
Actually, I would say that a much more dangerous teaching is one which states that in order to be saved you must continue to keep the Mosaic laws. What that says is that Jesus statement on the cross that "it is finished" was a lie.
Did not Jesus die for all your sins? What can you do besides claiming the blood of Jesus over your sins that will save you? Does living a good life free from the outward manifestations of sin save you? Does it keep you saved? Or are you saved wholly and totally by the saving grace of Jesus?
Are you, if you believe in Christ, capable of committing a sin that Jesus did not die for?