John 10:40

And went away again beyond Jordan, into the place where John at first baptized. In Bethabara, or Bethania, where Christ was baptized by him. He afterwards baptized in Ænon (see Joh 3:23), frequently shifting His abode. He went through other districts of Jordan, He withdrew to Bethabara, that the people who followed Him thither might call to mind the testimony which John had borne to Him on the very spot, and also the testimony of God the Father at His baptism, and might on this account believe in Him. So S. Chrysostom.

And there abode : till the Passover and his own Passion drew nigh, when He returned to Jerusalem, and raised up Lazarus, which provoked the scribes and rulers against Him. Ver. 41. And many resorted, &c. And yet we believed him. Therefore we ought the more firmly to believe in Jesus, who proves that He is the Messiah by so many signs and miracles. So S. Chrysostom.

There was also another reason for their believing in Christ; namely, that they found Him to be mightier than John in His miracles, in the power of His discourses, in His holiness of life, as John had foretold. And hence they inferred, If we see that the other things which John spake of Him are true, it is therefore equally true (as he said) that Jesus was the Messiah. Ver. 41 .