Here’s what the Venerable Bede wrote about this passage (Mark 10:17-18). It’s similar to what +John Chrysostomos taught. Interesting that the wording is almost identical to that from +Matthew. Some of the Fathers believed that +Mark was sort of an abridged version of an early version of the Gospel According to +Matthew:
“But by this one God, who is good, we must not only understand the Father, but also the Son, whom says, I am the good Shepherd; and also the Holy Ghost, because it is said, The Father which is in heaven will give the good Spirit to them that ask him. For the One and Undivided Trinity itself, Father, Son amid Holy Ghost, is the Only and One good God. The Lord therefore does not deny Himself to be good, but implies that He is God; He does not deny that He is good Master, but He declares that no master is good but God.”
In the present day he would be a highly paid Spin Doctor.