Therefore do not let anyone judge you by what you eat or drink, or with regard to a religious festival, a New Moon celebration or a Sabbath day. --Colossians 2:16Paul also reserves his harshest comments for those who make a distinction based on Jewish holidays and think that keeping these festivals somehow makes them closer to or more pleasing to the Lord.
One man considers one day more sacred than another; another man considers every day alike. Each one should be fully convinced in his own mind. He who regards one day as special, does so to the Lord.--Romans 14:5&6
If you believe that Paul is saying that we don't need to observe God given holy days, then why does he specifically tell gentile Christians to observe God given holy days:
1Co 5:2 And ye are puffed up, and have not rather mourned, that he that hath done this deed might be taken away from among you.
1Co 5:6 Your glorying is not good. Know ye not that a little leaven leaveneth the whole lump?
1Co 5:7 Purge out therefore the old leaven, that ye may be a new lump, as ye are unleavened. For even Christ our passover is sacrificed for us:
1Co 5:8 Therefore let us keep the feast, not with old leaven, neither with the leaven of malice and wickedness; but with the unleavened bread of sincerity and truth.
In the passages above, it is clearly the time of Passover and the feast of unleavened bread. Pauls numerous references to leavening are evidence of this. He then concludes with the REAL meaning of the feast of unleavened bread...that we are to diligently search our and remove sin from our lives as we search out and remove leavening. He specifically says to keep the feast!