When Paul says that Christ died for our sins according to the scriptures, the our here 1 Cor 15:3 are those who had a Representative union with Him; This Union that the Elect had with Christ when He died for their sins was just as real as the union they had with Adam when he was created and when they died with him, and this union they had with him was real even though had no personal individual being themselves, as well as before they performed any acts ! This Union is revealed to be real because of the real effects upon them by reason of the Union, that is from God's perspective they sinned when Adam sinned, the condemnation he incurred was theirs Rom 5:18 18 Therefore as by the offence of one judgment came upon all men to condemnation; even so by the righteousness of one the free gift came upon all men unto justification of life. And the penalty of death he incurred, they also in and with him incurred Rom 5:12 ! Now what understanding soul will deny the union of the Elect with Adam from this Truth of scripture ? And so in the like manner, the Elect of God were in Union with Christ by Divine Election Eph 1:4 [before their union with Adam in time] and when He experimentally took upon Himself a like Nature [saving sin] Heb 2:14-16 14 Forasmuch then as the children are partakers of flesh and blood, he also himself likewise took part of the same; that through death he might destroy him that had the power of death, that is, the devil; 15 And deliver them who through fear of death were all their lifetime subject to bondage. 16 For verily he took not on him the nature of angels; but he took on him the seed of Abraham. And He as the first Adam was, experimentally in the flesh, their Head, Surety and Representative and this Union with them was so real that when Christ for their sins was arraigned condemned and sentence Isa 53:6-8, they also by Union Representation were also considered the same, so much so that when He died for their sins they died 2 Cor 5:14; Gal 2:20, for the execution of God upon Christ their Union Head for their Transgressions against His law, was theirs ! Now this Union in Christ, as it was in Adam, was before any act of their own, before they had any physical being of their own ,however the fruit or effects of the Union are what give Evidence of the previous existing Representative Union; In fact their eventual Faith Union in Time is but an effect or fruit or result of their Union Representatively they had with Christ before Faith or before they had any being at all physically or Spiritually !