I loved this passage by Pope Benedict XVI on what it means to live sincerely, and what it means to constantly choose goodness over evil:

Sincerity is fundamental … People must feel that we are not saying words we ourselves have not lived, but that we speak because we have found and seek to find anew every day the truth, as a truth for my own life. Only if we have set out in this direction, if we ourselves seek to interiorize this life and to make our lives resemble that of the Lord, can our words be credible and have a visible and convincing logic. I repeat: today this is the great fundamental rule … for the whole of Christian life: choose life. … Only in this way is our horizon sufficiently broad and only in this way are we at the source of life, which is stronger than death, stronger than all death threats. Thus, the fundamental choice is the one pointed out here: choose God.