Ephesians 2: 8-9
For by grace you are saved through faith; and that not of yourselves: it is the gift of God; 9 not by works, so that no one can boast.
Grace is a favor, generosity, "unmerited favor." It is like a gift we receive. No one thinks of paying for a gift they received. Accepting God's grace is a great challenge, because we were created and formed with the religious thought that we should pay for sin, that we should be punished or suffer some deprivation. Hence the idea of penance, payment of promises, purgatory, etc. But we are saved by grace. This is difficult to understand because in the physical realm everything has to be paid, everything comes in return, human justice does not know what forgiveness is, because forgiveness comes from God.
First teaching: The gospel of grace is an act of love.
Luke 15: 20-24
And getting up, he came to his father. And when he was still far away, his father saw him, and he was moved with mercy, and he ran, and fell on his neck, and kissed him. 21 And the son said to him, Father, I have sinned against heaven and against you, and I am no longer worthy to be called your son. 22 But the father said to his servants, Take off the best robe, and clothe him; and put a ring on his hand, and shoes on his feet. 23 And bring the fatted calf and kill it, and let us eat and celebrate, 24 for this my son was dead, and he has revived; it was lost, and is found. And they began to rejoice.
In the parable of the Prodigal Son, that young man had no right, having already received his share of the inheritance and wasted it. Still, the father received him back. If we look at it from a human point of view, that was unfair, so the older brother did not accept his father's attitude. (Luke 15: 28-30.) From a human point of view, God's grace is unjust. That is, we did not deserve it because we voluntarily turned away from Him and took the opposite direction, thinking that we could do better than His instructions for us. But the love of God for us and the same love of the Father for the prodigal son of the parable.
Why do you think many people do not accept the gospel that we preach to them?
Second Teaching: The gospel of grace is for those who recognize that they need it.
Mt 9: 10-12
10 And it came to pass that while he was sitting at the table in the house, behold, many publicans and sinners, who had come, sat together at the table with Jesus and his disciples. 11 When the Pharisees saw this, they said to the disciples: Why does your Master eat with tax collectors and sinners? 12 When Jesus heard this, he said to them: The healthy do not need a doctor, but the sick.
Only those who acknowledge that they are sinners, that they have missed the mark, that they have gone astray and have turned their backs on the Creator and the Father, can take possession of grace. Grace manifests itself when there is humility. Jesus walked with sinners, tax collectors, prostitutes, and was condemned by religious authorities for this attitude. Jesus received sinners, but resisted the religious. Why religious do not recognize their sins. They think they are too good. They don't need grace, because they think they are without sin. They are only in themselves. Jesus came for sinners.
3rd Teaching: The gospel of grace is offered and not imposed.
Lk 9, 51-56
51 When the time had come for him to be received upstairs, he established his face to go to Jerusalem. 52 And he sent messengers before him, who went and entered a village of the Samaritans to make preparations for him. They received, because their appearance was like going to Jerusalem. 54 Seeing this, his disciples James and John said: Lord, do you want us to command fire to come down from heaven, as Elijah did, and consume them? 55 Then he turned and rebuked them. saying, You do not know what spirit you are of; 56 for the Son of Man has not come to lose the souls of men, but to save them. And they went to another village.
The Gospel, following the way of being of Jesus, is not imposed, but offered. Conversion forced or manipulated by a threat is not of God. The text read is one of the examples that makes it clear that Jesus never forced anyone to believe in Him. The best way to win people for Jesus is not by charging, but by example.
This is the time for you to throw away all your self-righteousness. You will never be able to pay the debt incurred for sin. The price is death itself, for what Jesus has already paid. The prodigal son would work all his life for the father and would not pay the debt, but he returned to sit at the table because the father forgave him. Salvation is by GRACE!