Christ has already stated specifically for whom He laid down His life for, do you believe Him is the question ? Jn 10:11-15 11 I am the good shepherd: the good shepherd giveth his life for the sheep. 12 But he that is an hireling, and not the shepherd, whose own the sheep are not, seeth the wolf coming, and leaveth the sheep, and fleeth: and the wolf catcheth them, and scattereth the sheep. 13 The hireling fleeth, because he is an hireling, and careth not for the sheep. 14 I am the good shepherd, and know my sheep, and am known of mine. 15 As the Father knoweth me, even so know I the Father: and I lay down my life for the sheep. Therefore the OUR SINS in 1 Cor 15:3 would refer to the Sheep ! Christ says that He knows His Sheep Vs 14 which we understand to meaneth He foreknew them all Rom 11:2 2 God hath not cast away his people which he foreknew. Wot ye not what the scripture saith of Elias? how he maketh intercession to God against Israel saying, And it should also be made clear that one does not have to be a believer in Christ to be one of His Sheep, for this is understood by Christ statement ' Other Sheep I have that are not of this fold [ethnic jews, but of the gentiles also] of which He says, them also I must bring, and they SHALL HEAR MY VOICE, which is the Gospel of their Salvation, and by that Hearing, Faith comes. Jn 10:16 16 And other sheep I have, which are not of this fold: them also I must bring, and they shall hear my voice; and there shall be one fold, and one shepherd. At that time, those Sheep in the gentiles, were unbelievers and Idolaters, but they were still His Sheep that He had. He had them because the Father had gave them to Him, and this ensured that they would Hear His Voice and Believe, another way of saying what He said in Jn 6:37 37 All that the Father giveth me shall come to me; and him that cometh to me I will in no wise cast out. They are given to Christ before they come to Him or Believe in Him ! Yet many deceivers would have us believe that one is not a Sheep of Christ until after they believe, which has now been proven to be error, a lie, by Christ's very words ! " Other Sheep I have" yet being uncalled by the Gospel as of yet to Gospel Faith and Obedience. Note: Even the unbelieving Sheep are never the goats, that shall hear this words soon Matt 25:33,41 33 And he shall set the sheep on his right hand, but the goats on the left. 41 Then shall he say also unto them on the left hand, Depart from me, ye cursed, into everlasting fire, prepared for the devil and his angels: And it is a lie, and cannot be supported by scripture that Christ laid down His Life for the goats , and He never said He did !