Let me rephrase, then:
Next time an LDS claims to be a Christian, ask them if, since you are a Christian, it would be accurate to refer to yourself as an LDS.
Yes we are the Latter Day Saints
Paul always refered to those in the Churches saints
2 Cor. 1: 1
1 PAUL, an apostle of Jesus Christ by the will of God, and Timothy our brother, unto the church of God which is at Corinth, with all the saints which are in all Achaia:
Eph. 1: 1
1 PAUL, an apostle of Jesus Christ by the will of God, to the saints which are at Ephesus, and to the faithful in Christ Jesus:
Philip. 1: 1
1 PAUL and Timotheus, the servants of Jesus Christ, to all the saints in Christ Jesus which are at Philippi, with the bishops and deacons: