For example, John 10:11, the Lord Jesus Christ said, I am the good shepherd: the good shepherd giveth his life for the sheep. It is very clear that Christ gave His life for the sheep. The sheep are everyone who will believe (the believing ones), because in John 10:26, Jesus said to unbelievers, But ye believe not, because ye are not of my sheep, as I said unto you.
Another scripture would be Romans 8:32, When in the context of these verses, God speaks of believers (elect), when He says, He that spared not his own Son, but delivered him up for us all, how shall he not with him also freely give us all things.
Even in John 3:16, it is the whosoever (the believing ones) who will be saved.
Christ's death is efficient only for the believing ones. Christ secured the salvation for all the believing ones on the cross, because the believing ones are the only ones who will receive salvation by God's grace through faith in the Lord Jesus Christ, and trust in Him to save them by His death, burial and resurrection.
