To underestimate a person might mean that we don't really expect much from that person, nor expect much of that person.
It could be that the person had disappointed us or did not live up to our expectations.
Or it could simply mean that we don't think much of that person's capabilities and so we "look down" on that person.
When the leper came up to Jesus and pleaded on his knees, he wasn't underestimating the ability of Jesus to heal him.
But it could be that he had suffered too many disappointments and rejections in life and so even as he came before Jesus, he wasn't expecting much.
Hence his words to Jesus was "If you want to, you can cure me", words that had a tone of pessimism and dejection.
The response of Jesus was astonishing as He said to the leper, " Of course I want to. Be cured!"
That might make us recall those times when we thought that Jesus didn't answer, or even didn't listen, to our prayer.
We felt disappointed and frustrated and we even get angry with Jesus.
Jesus wants to tell us that He certainly heard our prayer and even answered them.
But as the 1st reading says, let us not harden our hearts such that we cannot see how God has answered our prayer.
Let us also keep encouraging each other to keep faith in Jesus and to trust in Him.
For where two or three gather in His name in prayer, the prayers will be heard and answered.