The book of Genesis relates that Abel presented to Yahweh the first fruits and the best of his cattle. Abel's offering was pleasing to God, but Cain's was not, for he did not offer the best of his harvest.
Abel was "righteous," that is, holy and pious. What makes Abel's offering better is not its objective quality, but his dedication and generosity. This is why God looked with pleasure on his victims and perhaps sent - according to an ancient Jewish tradition - fire to burn them as a sign of acceptance.
Also in our life the best must be for God. We must present the offering of Abel and not that of Cain. For God must be the best of our time, of our goods, of our life. We cannot give him the worst, what is left over, what does not cost sacrifice or what we do not need. For God all our life, but including the best years. To the Lord all our goods, but, when we want to give him an offering, let us choose what is most precious, as we would do with a creature of the earth whom we esteem highly. Man is neither body alone nor soul alone; because he is composed of both, he also needs to manifest through external, sensible acts his faith and his love for God. Those people who seem to have time for everything, but hardly have time for God: for a time of prayer, or a visit to the Blessed Sacrament, which lasts only a few minutes..., are a pity. Or else they have the financial means for so many things and they are stingy with God and with people. Giving always enlarges the heart and ennobles it. From stinginess comes an envious soul, like that of Cain: he could not stand the generosity of Abel.
"It is necessary to offer to the Lord the sacrifice of Abel. A sacrifice of young and beautiful flesh, the best of the flock: of healthy and holy flesh; of hearts that have only one love: You, my God; of intelligences worked by deep study, that will surrender to your Wisdom; of childish souls, that will think only of pleasing you.
"Receive, from now on, Lord, this sacrifice in the odor of gentleness". For You, Lord, the best of my life, of my work, of my talents, of my goods..., even of those that I could have had. For You, my God, all that You have given me in life, without limits, without conditions.... Teach me not to deny You anything, to always offer You the best.
Let us ask the Lord to know how to offer Him in every situation, in every circumstance, the best we have at that moment; let us ask Him for many offerings and sacrifices like that of Abel: men and women who give themselves to God from their youth. Hearts that - at any age - know how to give Him everything that is asked of them, without haggling, without stinginess.... Receive, O Lord, this willing and joyful sacrifice!