BofM - introduction

 In his introduction, Moroni stated the this record is - 

"...to show unto the remnant of the house of Israel what great things the Lord hath done for their fathers; and that they may know the covenants of the Lord, that they are not cast off forever..."(Title Page, 2)

"...they have taken away from the gospel of the Lamb many parts which are plain and most precious; and also many covenants of the Lord have they taken away."  (1 Nephi 13:26)

“…behold, ye are the children of the prophets; and ye are of the house of Israel; and ye are of the covenant which the Father made with your fathers, saying unto Abraham: And in thy seed shall all the kindreds of the earth be blessed.

26 The Father having raised me up unto you first, and sent me to bless you in turning away every one of you from his iniquities; and this because ye are the children of the covenant—”  (3 Nephi 20:25–26)

One must enter into covenants to obtain the Celestial Kingdom.  Other kingdoms do not require covenants.