Time for a Hebrew lesson.
The word steadfast love translated in Hebrew is: checed (pronounced He-sed).
It is most often used in the Old Testament to express the active good-will and attitude of mutual blessing that exists between covenant partners (people that make a vow with one another, I.e. married couples.)
It describes the feeling and obligation of mutual blessing found between a husband and wife, two families joined through marriage, or two profound friends.
I believe that marriage vows are the strongest pledge of union possible between two people. Bride and groom pledge their futures together "for better, for worse; for richer for poorer; in sickness and in health; to love and to cherish till death do us part, according to God's holy ordinance; and thereunto; and thereto I plight thee my troth."
*[You may be thinking: Anthony, excuse me, but maybe you typed in the wrong ending. Did you mean to write the last phase? I plight thee my troth?
...Am I marrying a farm animal?]
That last phrase, "I pledge thee my troth" MEANS, "I pledge to you my most solemn vow and trust you to do so as well."
No matter what the future might hold, the bride and groom are melding their destinies for the rest of their lives and promising to do all within their power to protect, provide for and support one another ... no matter the consequences.
Then, the promise is sealed with a Ring.
A Ring that's circular in nature; that has no beginning and no ending...