God says “Love me or die”

[BioLogos]

I presume you're referring to the "greatest commandment" (You shall love the Lord your God with all your heart, mind and strength). The laws of the OT are given within the context of a covenant made between God and His people. In those days a covenant was like a contract made between two parties, where both promised to do certain things for one another. So God makes certain promises to His people (that He will protect them, make them multiply, etc.) and in return His people promise to live the way God wants them to live. To love God just means to live for Him: to do everything according to His purposes and not our own. The greatest commandment says that we should not do this just with our actions (our strength) but our emotions and thoughts as well. In loving God with our heart, mind and strength we live the way we were created to live: we are living out our true purpose, which is ironically more liberating than living the way we want to live. So God, in His love, urges us to live this way, for our benefit as well as for His joy.