Christ Jesus died for only One People according to God's Eternal Purpose Eph. 1:11 to save them from their sins: His People Mat. 1:21 which were Chosen of God In Union with Him before the foundation of the World [God's Elect], to Inherit the Eternal Kingdom Eph. 1:4-11, and the same are His Sheep which He gave His Life for John 10:11, 15.
You see, they're just different names for the same Chosen People !
Eph. 1:11 In whom also we have obtained an inheritance, being predestinated according to the purpose of him who worketh all things after the counsel of his own will.
Eph. 3:11 According to the eternal purpose which he purposed in Christ Jesus our Lord:
So when we compare scripture with scripture 1 Cor. 2:13 we can be assured that God only Loved One People: Those whom He Saved from their sins even before the World began.
This is referred to in scripture as the Gospel according to the Power of God 2 Tim. 1:8:
2 Tim. 1:9 Who hath saved us, and called us with an holy calling, not according to our works, but according to his own purpose and grace, which was given Him in Christ Jesus before the world began,
These are none other than God's Elect, which make up the Body of Christ; His Church He gave His Life for Eph. 5:25 which was given Him of the Father John 10:29, and which He shed His Blood for to Save them from their sins Heb. 9:22.
The same ones are called Israel, the only ones which were Promised Salvation:
Is. 45:17 But Israel shall be saved in the LORD with an everlasting salvation: ye shall not be ashamed nor confounded world without end.