Jesus died for the sins of the whole world. “He is the propitiation for our sins, and not for ours only but also for the sins of the whole world” (I John 2:2). Jesus died for all because “all have sinned and fallen short of the glory of God” Romans 3:23 Romans 5:12 says “Therefore, just as sin entered the world through one man, and death through sin, and in this way death came to all people, because all sinned” When all men became sinners in Adam, the only man after Adam to be born in this world without sin was Jesus. Only a man without sin can become the penalty for sin. Jesus was born without sin, lived without sin and hence became eligible to eliminate the sins of the world. Since the wages of sin is death, Jesus bore this death for the sins of all men, on the cross. There is no redemption without the shedding of blood, says the word of God. Jesus took death, as the punishment of sins of all mankind. He, in exchange of His sinless blood that is His life, got for us freedom from sin and reconciled us with God. Not only that He defeated death and resurrected and got His eternal life for all who believe in Him.
The only man to come to earth so qualified, is Jesus.
If we believe in our heart that Jesus died for my sins and rose up and if we confess Jesus as Lord with our tongue, we obtain forgiveness for our sins and eternal life. Eternal life is the life of God. This is the salvation which Jesus gives. Jesus died not for Christians but for sinners, because all have sinned and have lost the glory of God. Hence the death of Jesus was for the whole world, for me and for each one of you.