Lie not one to another

Lie not one to another, seeing that ye have put off the old man with his deeds

Col 3:9

Do not live a lie. Do not conform just to get along or please people, all the while hiding rebellion in your hearts and secretly desiring the things of the world. Examine yourself and put away those things, for they are the ways of death.

Remember you are risen in Christ and seek those things which are above.

Liberty

Romans is addressing the liberty we have concerning the ceremonial and dietary laws, but we do not have liberty concerning moral law.

Biblical feast days and sabbaths are ceremonial and shadows of things to come. We have liberty concerning them as Jesus has or will fulfill them.

The practice of traditions of men, doctrines of devils and pagan practices is a moral issue, as God has expressly called it abomination.