But Thomas, one of the twelve, who was called Didymus, was not with them when Jesus came. So the other disciples were saying to him, “We have seen the Lord!” But he said to them, “Unless I see in His hands the imprint of the nails, and put my finger into the place of the nails, and put my hand into His side, I will not believe.”
Eight days later His disciples were again inside, and Thomas was with them. Jesus came, the doors having been shut, and stood in their midst and said, “Peace be to you.” Then He said to Thomas, “Place your finger here, and see My hands; and take your hand and put it into My side; and do not continue in disbelief, but be a believer.”
Thomas answered and said to Him, “My Lord and my God!”
Jesus said to him, “Because you have seen Me, have you now believed? Blessed are they who did not see, and yet believed.”
John 20:24-29
We can understanding why some people have a difficult time believing that Jesus is the Son of God and the Savior of the world when we consider that Thomas, who was one of His disciples did not believe that the other Disciples had seen the resurrected Jesus.
Thomas' doubts mirror what many people feel when the truth of the Gospel is presented. They cannot see a purpose to it or a reason that they would want to ask Jesus to be their Lord, Master and Savior. Their doubt is real.
When I was a young adult, I had a friend who thought because I was "religious" I should become a nun. I had shared the Gospel with her, but she did not get it and thought I was religious nut. We lost contact and then years later, she called me and said that she had became a Christian and she knew what I meant about love of God.
That being said, we should not put too much stock in those who reject our message because others will come along with the Gospel message and they may be receptive to it because those words we spoke to them have settled in their hearts.