Generally people recognize that general promises in the scriptures are applicable to themselves as well. This is captured in the Lord’s statement to Emma Smith. The revelation is addressed directly to her, but then adds:
D&C 25:16 And verily, verily, I say unto you, that this is my voice unto all. Amen.
It is also found in other places.
D&C 61:18 And now I give unto you a commandment that what I say unto one I say unto all, …
D&C 82:5 Therefore, what I say unto one I say unto all: …
D&C 93:49 What I say unto one I say unto all;
And quite possibly what these are getting at is actually summed up in D&C 130.
D&C 130:20 There is a law, irrevocably decreed in heaven before the foundations of this world, upon which all blessings are predicated –
21 And when we obtain any blessing from God, it is by obedience to that law upon which it is predicated.
If we will do that which is commanded, we will get the blessing. And if the Lord explained a commandment and blessing to one person, another can gain the same blessing by paying attention to that.
Not that we can gain every particular that was related to time and circumstances. At one time the Lord commanded “Thou shalt not kill”, and at another time he commanded “Thou shalt utterly destroy”.
But what spiritual blessing will God withhold for obedience now that he previously gave for obedience then to the saints of Joseph day, of Christ’s day, or of any day in which the earth has stood?