It is so deceivingly easy to speak on behalf of those who are no longer on Earth to speak for themselves. So let us stick with what saint Paul has said in his writings and not put our own words into his mouth.
Saint John explicitly states:
Whoever confesses that Jesus is the Son of God, God abides in him, and he in God. So we know and believe the love God has for us. God is love, and he who abides in love abides in God, and God abides in him. In this is love perfected with us, that we may have confidence for the day of judgment, because as he is so are we in this world. There is no fear in love, but perfect love casts out fear. For fear has to do with punishment, and he who fears is not perfected in love. (1 John 4:15-18)
Saint Paul explicitly states:
What then? Are we to sin because we are not under law but under grace? By no means! Do you not know that if you yield yourselves to any one as obedient slaves, you are slaves of the one whom you obey, either of sin, which leads to death, or of obedience, which leads to righteousness? But thanks be to God, that you who were once slaves of sin have become obedient from the heart to the standard of teaching to which you were committed, and, having been set free from sin, have become slaves of righteousness. I am speaking in human terms, because of your natural limitations. For just as you once yielded your members to impurity and to greater and greater iniquity, so now yield your members to righteousness for sanctification. When you were slaves of sin, you were free in regard to righteousness. But then what return did you get from the things of which you are now ashamed? The end of those things is death. But now that you have been set free from sin and have become slaves of God, the return you get is sanctification and its end, eternal life. For the wages of sin is death, but the free gift of God is eternal life in Christ Jesus our Lord. (Romans 6:15-23)
Set free from sin and living in the love of God which casts out fear Christians are called to celebrate God's goodness and his graces every day. No day is impure and no celebration of the saving work of Christ in his incarnation, life, suffering, and death is wicked nor is the celebration of Christ's triumph over the grave and ascension to heaven. Finally, we are called to look for and anticipate the advent of Christ at the and of the ages when he shall sit in judgement of the whole world and give his blessing to those who serve God. Thus we need not fear the 25th of December nor ought we to religiously avoid celebrating Jesus first and second advents but rather we ought to celebrate these things in accordance with the Church's provisions for these holy days. Pagan gods are no gods at all and we need not fear their days or months or years.
