Scriptures that show the efficaciousness of the death of Christ, that it actually saves, and so those who are not being saved, Christ did not die for them..
Jn 12:
23And Jesus answered them, saying, The hour is come, that the Son of man should be glorified.
24Verily, verily, I say unto you, Except a corn of wheat fall into the ground and die, it abideth alone: but if it die, it bringeth forth much fruit.
Christ saving death is how He is Glorified..
Jesus here in these verses is speaking of Himself and the Church, His body.. For it shall come forth out of death with Him, a Living and Spotless Church, Justified by His blood and righteousness.
Its a faithful saying, if we be dead with Him, that is died when He died [ 2 cor 5:14-15] we shall also live with Him, that is experience the power of His resurrection..
All for whom He died, will be raised from spiritual death, begotten unto a lively hope, how ? By the resurrection from the dead 1 pet 1:
3Blessed be the God and Father of our Lord Jesus Christ, which according to his abundant mercy hath begotten us again unto a lively hope by the resurrection of Jesus Christ from the dead,
So as Jesus states in Jn 12 24, His death [ to include His resurrection] brings forth much fruit..That is, it actually produces positive results and benefits for them He died..