From The Healing Power of the Eucharist
How do we receive grace? There are three major avenues. First of all, we can receive grace through some form of prayer: prayer of blessing and adoration, prayer of petition, intercessory prayer, prayer of thanksgiving, or prayer of praise. Likewise, it can be any expression of prayer: vocal prayer, meditation, contemplative prayer, community prayer, liturgical prayer, or psalm prayer.
The second major source of that spiritual energy we call grace comes from practicing the virtues, such as faith, hope, charity, prudence, justice, fortitude, and temperance. In fact, some 56 virtues have been cataloged over the years. (Even suffering could be considered a virtue when it is motivated by love, since it could be a manifestation of the virtues of fortitude, perseverance, mortification, temperance, and self-control.)
The third source of grace is the seven sacraments. Of the seven sacraments, only two – the sacraments of reconciliation (penance) and the Eucharist – may be received frequently. And of the seven, the Eucharist is the greatest source of grace. When we receive the Eucharist, we receive not only grace but the very Author of Grace; in receiving the Eucharist, we do not receive a thing but God himself in his human nature as Christ and his divine nature as God. Consequently, the Eucharist transcends any other source of grace, and as Saint Thomas Aquinas asserts, it is the ultimate focal point of all the other sacraments.
We can attain great holiness by prayer alone. We can also attain advanced holiness by practicing any one of the virtues, since the full spectrum of virtue grows, as Saint Thomas explains, the way the hand grows – not one finger at a time but all together. As one finger grows, the other fingers grow simultaneously. Likewise, as we practice any one virtue, the other virtues will grow too. But when it comes to maximizing our holiness, nothing exceeds the sacraments as a source of grace. The seven sacraments are designed by God to be the main avenues of our encounter with him, and among the sacraments, the Eucharist is the greatest in terms of conferring grace and having the power to make us holy.