The parable of the "treasure hidden in the field" and the "merchant man seeking goodly pearls" appear intended to convey one and the same lesson (
These two parables are meant to teach us that men really convinced of the importance of salvation will give up everything to win Christ and eternal life.
What was the conduct of the two men our Lord describes? The one was persuaded that there was a "treasure hidden in the field," which would amply repay him - if he bought the field - however great the price that he might give. The other was persuaded that the "pearl" he had found was so immensely valuable that it would compensate him to purchase it at any cost. Both were convinced that they had found a thing of great value. Both were satisfied that it was worth a great present sacrifice to make this thing their own. Others might wonder at them. Others might think them foolish for paying such a sum of money for the field and pearl. But they knew what they were about. They were sure that they were making a good bargain.
In this single picture, the conduct of a true Christian is explained! He is what he is and does what he does in his religion because he is thoroughly persuaded that it is worth it. He comes out from the world. He puts off the old man. Like Matthew, he gives up everything, and, like Paul, he "counts all things loss" for Christ's sake. And why? Because he is convinced that Christ will make amends to him for all he gives up. He sees in Christ an endless "treasure." He sees in Christ a precious "pearl." To win Christ he will make any sacrifice. This is true faith. This is the stamp of a genuine work of the Holy Spirit.
Adapted from The Gospel of Matthew by J.C. Ryle (Chapter 13).