In its very essence is the driving passion of our Lord and Savior, Jesus Christ. He never ceases to pursue his prize, every person that walks the face of the earth are the object of Christ's love. He so desires to be the object of our desire, something that the song clearly states...
"You won't relent until you have it all"
Showing that Jesus isn't satisfied with just your mediocre efforts, he tells the Laodiceans in Revelation,
"I wish that you were hot or cold, but because you are not, I am about to spit you out of my mouth."
The idea is that the Laodiceans were riding the fence of faith, not living in the world, but being worldly... But additionally I see God's heart for his believer, not 50% or even 98%, but all in, he desires that we give him as much as he gave you and I in relentless pursuit of our soul. But this idea goes well beyond the believer.
"But God shows his love for us in that while we were still sinners, Christ died for us."
God's relentless love started before you believed in Jesus Christ, this gives the magnificent realization that Christ died for our sins before we ever committed them. That is because Christ died for you before you or I were born!
That is relentless love! So we gallantly accept this love, we feel forgiveness and grace pour over us sinners... But we often forget Romans 5:8, that Christ died for us while we were still sinners, it also means that Christ died for you enemies, for your neighbor or co-worker that doesn't believe in Jesus, he died for your brother, your sister, yes even your in laws....
God's amazing love, it is relentless, in pursuit of people til death do we part... It never fails, it bridges over theological gaps, and is worthy of praise.
But we must also, as believers, relentlessly pursue non-believer's in the same love and grace that Jesus pursued us, when we were yet non-believers. We are truly at war, but our battle isn't against flesh and blood, but against spirit! If we aren't in pursuit of non-believers, don't fool yourself into thinking, that the enemy isn't in pursuit of them either! We are in a race against time, God desires that no one should perish, but that all should have eternal life! Hence God is in pursuit of all people!!!! And he has been since before the creation of humanity! That is relentless love! Filled with love and compassion, stepping in, in the midst of our struggle and pain! Telling us that he loves us! Regardless of what you've done or said... He loves you right now! He's not after some fairy tale version of you, he wants you in all your discontent, in your pain, your anger, your failure!!! He won't relent! Not until he has you!
I hope that this message encourages you to know that our lord and God loves you so much!