God's free initiative demands man's free response, for God has created man in his image by conferring on him, along with freedom, the power to know him and love him. The soul only enters freely into the communion of love. God immediately touches and directly moves the heart of man. He has placed in man a longing for truth and goodness that only he can satisfy. The promises of "eternal life" respond, beyond all hope, to this desire:
If at the end of your very good works . . ., you rested on the seventh day, it was to foretell by the voice of your book that at the end of our works, which are indeed "very good" since you have given them to us, we shall also rest in you on the sabbath of eternal life.
Source: Catechism of the Catholic Church (Vatican.va)