Can one be holy at all in this present world of ours?
Yes you can. It is impossible by your work, but God has made it easier because he loves us. He sent his righteousness/holiness through and in his son, Jesus. All you need do is believe on his son Jesus and holiness is imparted in you. Forget your weaknesses as human that you see even after you believe, God still sees you as he sees Christ. Better still, he looks at you but sees sees Christ instead.