When David repents for his sins in Psalm 50 (http://www.newadvent.org/bible/psa050.htm), his plea is so heartfelt and passionate, I cannot image anything but God smiling at his wayward son. I especially love the request repeated throughout the Psalm that asks God to "blot out my inequities." How often have you felt the same way? I feel like that often, especially when in all of my humanness, I repeat the same sins over and over. In verse 13 he says, "Cast me not away from thy face; and take not thy holy spirit from me." Can you imagine how dark it would truly be if God did not shine his face down upon us? That must be what is described when the darkness of the Valley of Death is described. The Holy Spirit is probably the least appreciated of the Trinity. We often praise God and pray to Jesus Christ but forget that the Holy Spirit is with us always. The third person of the Holy Trinity is also described as the Holy Ghost, the Paraclete, the Advocate, the Spirit of Truth, the Spirit of God, and the Spirit of Love. Because of the oneness of nature in the Blessed Trinity, the Father is entirely in the Son and in the Holy Spirit; the Son is entirely in the Father and in the Holy Spirit; and the Holy Spirit is entirely in the Father and in the Son. No one of the three divine Persons is outside the other, for none precedes the other in eternity, nor surpasses the other in power, nor exceeds the other in any way. This indwelling of one divine Person in the others is called circumincession. The Holy Spirit is always hard at work for us and the sanctification of mankind is attributed to the Holy Spirit because He is the love of the Father and the Son and because the sanctification of man by grace shows forth God's boundless love. St. Augustine called the Holy Spirit the greatest gift from God and I have to agree.