If you believe Jesus and trust that His Atonement that he secured on the cross paid the price for your sin, You already have the covering of His atonement.. So therefore why would you need to ask for it from Him ?
If you already have it then you have it.. Have Faith in Him..
And yeah totally disregard those who have no idea about the symbolism within Christianity and will use your question as an opportunity to have a cheap shot with pathetic mockery.. The LORD shall deal with them in time..
(Luke 18:7-8) "And shall not God avenge his own elect, which cry day and night unto him, though he bear long with them? {8} I tell you that he will avenge them speedily. Nevertheless when the Son of man cometh, shall he find faith on the earth?"