1. The funeral is first for praying for the dead, not celebrating their life. Celebrations of life are not consistent with Catholic theology. There is something very final in celebrating the life of one who has died. As Catholics, we know that death is not the end. We know that the person still has a journey to make. So, we pray for that person to complete the journey. If he be in purgatory, we pray for his release, so he may view the beatific vision. If he be in heaven (a canonized saint), we ask for his intercession to the almighty. We know that Hell exists and that there are souls there, but we don't assume any one person to be there. To celebrate the life of a person, is a denial, no matter how slight of the journey that he still has to make.
2. A funeral, for the living, is a form of comfort. For we see the person who has died off to the next step of his journey. Look at the final commendation prayers:
- May Angels lead you into paradise;
- may the Martyrs receive you at your coming
- and lead you to the holy city of Jerusalem.
- May a choir of Angels receive you,
- and with Lazarus, who once was poor, may you have eternal rest.
3. The reading for the funeral also opens the door to a continued life. Please view Wisdom 3:1-10.
 But the souls of the just are in the hand of God, and the torment of death shall not touch them.  In the sight of the unwise they seemed to die: and their departure was taken for misery:  And their going away from us, for utter destruction: but they are in peace.  And though in the sight of men they suffered torments, their hope is full of immortality.  Afflicted in few things, in many they shall be well rewarded: because God hath tried them, and found them worthy of himself.
 As gold in the furnace he hath proved them, and as a victim of a holocaust he hath received them, and in time there shall be respect had to them.  The just shall shine, and shall run to and fro like sparks among the reeds.  They shall judge nations, and rule over people, and their Lord shall reign for ever.  They that trust in him, shall understand the truth: and they that are faithful in love shall rest in him: for grace and peace is to his elect.  But the wicked shall be punished according to their own devices: who have neglected the just, and have revolted from the Lord.
We should pray at a funeral, not to celebrate the life of one who has lived an earthly life, but rather we should pray at a funeral for the soul who still has a journey to make. And we should pray unceasingly for that soul that his time to heaven be short and that his eternal rest is granted.
I will leave this post with the 15th stanza of the Dies Irae:
Grant me a place among the sheep,
and take me out from among the goats,
setting me on the right side.