if you go on the basis that all in the end will be saved then why is anyone need be a Christian?
First off, the Scriptures do not use the word Christian to describe the Body of Christ. Paul never used it in any of his letters to us. There is a reason for that.
The word Christian, "little-Christs"was primarily used in derision, to target and disparage the early disciples of the Lord. It has morphed into a general classification of all who are now believers. It is a negative appelation in the word of God, and should have remained that way. But now the sense of the word has been so altered that it is most unlikely to return to the way it is used in Scripture.
Being a "Christian" is not a personal choice, it is a response to the proclamation of the Cross of Christ, and believing on the Son of God. This alone is the qualification for life in the age to come. And this is from the God Who has made the hearing ear and the seeing eye. No man can receive anything if it does come from God first.
Jn 3:27 John answered and said, A man can receive nothing, except it be given him from heaven.
Becoming "Christian" is not in the hands or control of men, who would surely foul things up. It is an appointment by God, administered in grace to show forth His merciful goodness.
Ro 8:30 Moreover whom he did predestinate, them he also called: and whom he called, them he also justified: and whom he justified, them he also glorified
Eph 1:4 According as he hath chosen us in him before the foundation of the world, that we should be holy and without blame before him in love:
If the saints of God could grasp the reality of these things, that we were elect and chosen in Christ from before the disruption of the world, and walking according to a Power outside of ourselves, it would become obvious no one becomes a "Christian" unless it is appointed by God. Anything else would be a work of the flesh, and subject to the boasting of man. Unfortunately, this boasting occurs all too frequently as it is, with saints making the claim "I accepted Christ" or " I chose Christ".
Becoming a member of the Body of Christ is outside the control of man. It is not for everyone everywhere, as it's function is future, as the complement in the heavens with the Christ, reconciling the powers and principalities and forces of wickedness that now inhabit the celestial realm. We have work to perform ahead of us at His coming for us. It is not for all to enter into this grace and privilege.
1C 1:26 For ye see your calling, brethren, how that not many wise men after the flesh, not many mighty, not many noble, [are called]:
1C 1:27 But God hath chosen the foolish things of the world to confound the wise; and God hath chosen the weak things of the world to confound the things which are mighty;
AV 1C 1:28 And base things of the world, and things which are despised, hath God chosen, [yea], and things which are not, to bring to nought things that are:
AV 1C 1:29 That no flesh should glory in his presence.
It is God Who choses, not man. The Body has its place in God's plan of redemption, but we are not sole object, and the Scriptures make that plain. We have an inheritance with the Christ of God, but that inheritance includes the reconiliation of all things, whether they be in the earth or in heaven.