The best thing in the Bible might be Exodus 34:6-7.
And the Lord passed before (Moses) and proclaimed, “The Lord, the Lord God, merciful and gracious, longsuffering, and abounding in goodness and truth, keeping lovingkindness for thousands, forgiving iniquity, transgressions, and sin, by no means clearing the guilty, visiting the iniquity of the fathers upon the children and the children’s children to the third and fourth generation. “
It’s the best because it’s God’s self-revelation and it reveals Him to be pure love. Exodus 34:6-7 is the Old Testament corollary to I John 3:8,16 which say “God is love.”
Exodus 34:6-7 is the best because it’s quoted all through the Old Testament. Moses prayed it in Numbers 14:18. Nehemiah sang it in Neh. 9:17. Joel held it out as the reason God’s people could expect revival, in Joel 2:13. David sang it in Psalms 86:15, in 103:8, and in 145:8. Jonah complained about it in Jonah 4:2. And we find fleeting quotes from it throughout Jeremiah, such as in 32:18.