Someone or something you definitely could not live without.
I absolutely could not live without my husband. He is by far the best man I have ever known. He loves me like no other and is the best friend I could ever have. He supports me in my decisions but still offers wisdom when I need it. He is the embodiment of love presented in 1 Corinthians 13:4-8 "Love is patient, love is kind. It does not envy, it does not boast, it is not proud. 5 It does not dishonor others, it is not self-seeking, it is not easily angered, it keeps no record of wrongs. 6 Love does not delight in evil but rejoices with the truth. 7 It always protects, always trusts, always hopes, always perseveres.8 Love never fails."
Not to sound overly gushy, but I have the best husband ever and could not live without him.