ACTUAL GRACE
Actual Grace is that help from God which enlightens our reason and moves our will to do good and to avoid evil.
The conversion of St. Paul on his journey to Damascus, to persecute the Christians there, is an inspiring example of Actual Grace.  A light from Heaven enlightened his mind, and the voice of Jesus in the clouds moved his will.  He co-operated with this Grace, was converted, and became the great Apostle of the Gentiles. (Acts 9).
Actual Grace is so necessary to us that without it we cannot begin, continue, or accomplish the least thing towards our eternal salvation.  “Without Me you can do nothing.” (John 15:5).
Actual  Grace comes to us through various channels: the Sacraments, Prayer, Sermons, Good Works, Sickness, and the Good Example of Others.

SANCTIFYING GRACE

Sanctifying Grace is an unmerited gift of the Holy Ghost, whereby we become children of God and heirs of Heaven.  Sanctifying Grace is the supernatural life, beauty, and brightness conferred on our soul by the presence of the Holy Ghost.  It makes our soul the object of the special love and friendship of god.  “Know you not, that you are the Temple of God, and that the Spirit of God dwelleth in you?” (1 Cor. 3:16).

Without Sanctifying Grace, we cannot merit anything for Heaven.
“Abide in Me, and I in you.  As the branch cannot bear fruit of itself, unless it abide in the vine, so neither can you, unless you abide in Me.” (John 15:4).

Deeds or works that are performed in the state of Sanctifying Grace are meritorious; that is, they have an eternal value in the kingdom of Heaven.   “Every good tree bringeth forth good fruit, and the evil tree bringeth forth evil fruit.” (Matt. 7:17).

The Blessed Virgin Mary enjoyed a fullness of Sanctifying Grace.  “And the Angel being come in, said unto her: Hail, full of Grace, the Lord is with thee.” (Luke 1:28).

The Grace of Perseverance is a special divine gift, whereby we are helped to continue in the service of God until death.  “Be thou faithful unto death: and I will give thee the crown of life.” 

(Apoc. 2:10).
 

GOOD WORKS

Good works are deeds:
     Pleasing to God
     Meritorious for Heaven.

Good Works are necessary for salvation.  “Faith, if it have not works, is dead in itself.” (James 2:26).
“Every tree therefore that doth not yield good fruit, shall be cut down, and cast into the fire.”

(Matt 3:10).

To be pleasing to God and meritorious for Heaven, our deeds must be performed in the state of Sanctifying Grace and with the good intention.  “As the branch cannot bear fruit of itself unless it abide in the vine, so neither can you, unless you abide in Me.” (John 15:4).

The Bible especially recommends the following Good Works: Prayer, Fasting, and Alms-deeds.  “Prayer is good with fasting and alms more than to lay up treasures of gold.” (Tob. 12:8). 

A very important thing to remember about Good Works is the Good Intention.  The Good Intention is the desire to serve God and honor Him.  We may briefly form a Good Intention by saying: “All to the greater honor and glory of God.”  The Good Intention should especially be made in the morning.
Eating, Drinking, Studying, Working, Playing, Resting can become Good Works, if we perform them in the state of Sanctifying Grace and with the Good Intention.  “Whether you eat or drink, or whatsoever else you do, do all to the glory of God.” (1 Cor. 10:31).