The rightness of God is obvious, but only to those who desire to be right with God.  After Mark has recorded a battery of questions from the cynically rebellious hearts of the religious leaders, this man was willing to listen to Jesus' answer.  More than that - he could see that what Jesus said made sense ... not just to his own reason, but according to the Scriptures.  The Jewish creed, (Numbers 15:37-41; Deuteronomy 6:4-9, 11:13-21) that he had learnt as a child, and still repeated every day, validated what Jesus said about the need to love God wholeheartedly.  Samuel's second rebuke to Saul in 1 Samuel 15:22, shaped his response to the second part of Jesus' answer.  

The problem with Saul was that he wanted God to honour him and serve him, rather than having any obligation to honour God by obeying what God had said.  In 1 Samuel 13:11-14, Saul presumed to take the role of a priest in front of his people – to make himself look good.  That was when Samuel’s first rebuke announced that Saul was not a 'man after God’s own heart', that his kingdom would go to another who did want to be right with God.  Obedience is always better than religious activity which covers disobedience.

The man Jesus had spoken to knew that Jesus was right because what He said agreed with the Scriptures.  And that is still the only way to be sure of what is true. The scribe neither manipulated Jesus nor the Scriptures - he took them as having equal authority - which indeed was true.  Jesus identified wisdom in the man because he rightly says that the words of Jesus matched the written Word of God; in contrast to the previous verbal challengers who tried to trap Jesus.  If the Word of God is rejected, there is no other source of wisdom (Jeremiah 8:9).  

Alas today's religious philosophers make themselves wiser than both.  Proverbs 26:12 says, "Do you see a person wise in their own eyes?  There is more hope for a fool than for them."  To defy the Scripture is to defy Jesus - and He is the Judge who is always right! (Genesis 18:25b).  To agree with Scripture, is to agree with Jesus - who is the Word of God. It is hardly surprising that the only objective reference point we have about the mind of Jesus, the Bible, is under attack. But when we love the Word of God and conform our lives to it, how well our minds are settled and what spiritual productivity results as we live out the wisdom of Christ (1 Corinthians 1:24)!