D&C 132

There are a few in the Church that believe that once they are married for time and all eternity, all is done. The Lord said -

"...as pertaining to the new and everlasting covenant, it was instituted for the fulness of my glory; and he that receiveth a fulness thereof must and shall abide the law, or he shall be damned, saith the Lord God." (Doctrine and Covenants | Section 132:6)

Note the emphasis on "shall abide the law". The Lord continues -

"...the conditions of this law are these: All covenants, contracts, bonds, obligations, oaths, vows, performances, connections, associations, or expectations, that are not made and entered into and sealed by the Holy Spirit of promise, of him who is anointed, both as well for time and for all eternity, and that too most holy, by revelation and commandment through the medium of mine anointed, whom I have appointed on the earth to hold this power (and I have appointed unto my servant Joseph to hold this power in the last days, and there is never but one on the earth at a time on whom this power and the keys of this priesthood are conferred), are of no efficacy, virtue, or force in and after the resurrection from the dead; for all contracts that are not made unto this end have an end when men are dead." (Doctrine and Covenants | Section 132:7)

The conditions are these that 1) they made or entered into, 2) by one having authority to do so, and 3) sealed by the Holy Spirit of promise. They Holy Spirit may seal and even unseal do to the faithfulness of the individual. This becomes apparent as the Lord shares this example -

"...I say unto you, if a man marry a wife, and make a covenant with her for time and for all eternity, if that covenant is not by me or by my word, which is my law, and is not sealed by the Holy Spirit of promise, through him whom I have anointed and appointed unto this power, then it is not valid neither of force when they are out of the world, because they are not joined by me, saith the Lord, neither by my word; when they are out of the world it cannot be received there..." (Doctrine and Covenants | Section 132:18)

I believe the wording "not by me or by my word" suggests obedience to His words or commandments for -

"Verily, verily, I say unto you, except ye abide my law ye cannot attain to this glory.
22 For strait is the gate, and narrow the way that leadeth unto the exaltation and continuation of the lives, and few there be that find it, because ye receive me not in the world neither do ye know me." (Doctrine and Covenants | Section 132:21 - 22)

In the new and everlasting covenant, all conditions have to be satisfied to receive the promised blessings.