First let me say what some are thinking. This sounds like a bad word, but I assure you it is perfectly safe for everyone to know and use. :)
A couple of Sundays ago we sang the hymn “O Worship the King.” One of the lines reads “ O measureless might, ineffable love.” I don’t think I have ever taken the time to really think about these words as I am singing them.
Ineffable perfectly describes God. He is holy and majestic to such an extent that words fail to properly express it. His love is extravagant in every way, his generosity is excessive, his kindness is outrageous. He and his love are extreme.
At times I am rebellious, unfaithful, distrustful and idolatrous but he loves me anyway. I ignore his commands, neglect his word and ignore his wisdom but he does not turn his back on me. I disbelieve his promises, forget his faithfulness, and yet he answers my prayers and provides for me over and over again.
I deal unkindly with my kids but he is kind to me. I may be rough in my words but he is gentle with me. I don’t love others like I should or fail to work with all might at the job God has given me but he remains constant in all his goodness.
I am sinful and yet he who is high and lofty, whose very nature is ineffably pure has chosen to make his home in my heart. To His immaculate eyes, the heavens are unclean (Job 15:15), "the stars are not pure in his sight" (Job 25:5) but he draws near to me, to comfort and care for me.
His love is not just a fuzzy feeling he has for me, it is an affection that leads to action -- the extreme action of death.
God shows his love for us in that while we were still sinners, Christ died for us.