Matthew 22:37 English Standard Version (ESV) And he said to him, “You shall love the Lord your God with all your heart and with all your soul and with all your mind.
Mark 12:30 English Standard Version (ESV) And you shall love the Lord your God with all your heart and with all your soul and with all your mind and with all your strength.’
Luke 10:27 English Standard Version (ESV) And he answered, “You shall love the Lord your God with all your heart and with all your soul and with all your strength and with all your mind, and your neighbor as yourself.”
These are three different accounts of the same incident. The issue here is not truth. All are true. Variations in text vary for different reasons. John Mark wrote the Gospel of Mark. It was unlikely that he was in attendance at the time it was said. The same goes for Luke because at the time Luke was a physician. Matthew was likely to have been an eyewitness to those words as they were spoken.
So what does this matter in the scheme of things if we consider that all were inspired by God through the power of the Holy Spirit? It is because we all have the power of the Holy Spirit within us and we all hear differently. That is not a matter of truth nor is it a matter of memory. It has more to do with what we need to hear to believe.
When it comes to the Holy Spirit speaking truth to us in any circumstance it is more important to hear, to understand and to believe than it is in the mincing of words. Slight variations of text or the memory of text or the version of scriptures are not worth correcting when observed. We are human and with that comes a variety of personal preferences, style, and habits. Each one has some influence on communication. Some are so unimportant that everyone should ignore them.