Yes it is, a valid response, and I know the truth hurts but it's real. Take a look at the world today, there is genuine evil in this world, what is happening today is truly the work of the devil, from the performance at the grammy awards, to the commonwealth games opening ceremony, in music, in the media, and in general. And if you want to argue, whether the devil exists or not, and if you don't think sin is in everyone, your not taking a very close look at the world. By extension God must be real. No one said that when someone is born they are evil to the core. We have free will to do whatever we want, and because of human nature the flesh willingly wants to sin. Sin is disobeying God. Ever told a lie? You're a liar. You're a sinner. Our hearts are wicked, and that needs to be compensated. How can it be tho? By the blood of Jesus the Son of God; He took on the wrath of God. I suggest you read the Bible, then look up the Shroud of Turin. The greatest miracle has already occurred, that being the Creation. The Bible said in the beginning God created the heavens and the earth; 200 years ago scientists believed the universe had always existed; 60 years ago they found out it had a beginning. Since the beginning, which may well have been over billions of years ago, there was angelic rebellion against God, which led to Lucifer and a third of the angels being cast out of heaven (Isaiah 14:12-14). He fell to the earth (Luke 10:18), and brought sin into it through him. When Eve ate the apple and shared some of it with Adam, they disobeyed God, and this is sin. Through them, we are all sinners. I mean you can try (well not anymore because you have already from birth), but if you ever have a child try raise them so they don't sin; stealing, lying, fighting, whatever. Problem is, you can't, they will. If there's something I can predict, it would, be that. But thankfully, Jesus, who is God and proved He was God and took on the full human limitations by taking on the flesh, provides not a way but the way for us to receive mercy, that we don't deserve –when He, took on the wrath of God, upon the Cross, 2000 years ago. If you want to freely receive that gift of salvation, just confess your sin to Him, and He will save you.