Regarding food, sacred days, and probably clothing and other similar things, Paul says “…keep between yourself and God”. When we embrace cultural heritage it’s something to watch out for

“Each of us will be accountable to God” (v. 12). Therefore, 1) Let’s not be judgmental (vv. 4, 13), 2) Let’s live in honor of the Lord (v. 6), 3) Let’s pursue what makes for peace and for mutual upbuilding (v. 19).

v. 4 Who are you to judge someone else’s servant? Every one is God’s servant. I better not judge. Isn’t the hands that created me in my mother’s womb created the other person as well? I better not judge.

If the above comment is true, we can not even discipline our kids? How can we discriminate right/wrong?

Saying what you did is wrong is discipline. Saying you are bad as you did wrong is judging. As far as I know.

Sorry anybody can enlighten ” judging” here

You mean we can judge actions not the person ? That makes sense

Can someone explain more? How this verse will fit in our spiritual and day to day life?

Our God is the God of the Weak and the Strong, the Dead and the Living, the Poor and the Rich, and God of Everyone. God accepts whoever accepts Him! And, they are His servants, He is “the” Master.
-(v9) For this very reason Christ died and returned to Life so that He might be the Lord of both the dead and the living.
-(v10) You, then, why do you judge your brother or sister (His servants)? Or, why do you “treat” them with contempt?

6 நாட்களை விசேஷித்துக்கொள்ளுகிறவன் கர்த்தருக்கென்று விசேஷித்துக் கொள்ளுகிறான், நாட்களை விசேஷித்துக் கொள்ளாதவனும் கர்த்தருக்கென்று விசேஷித்துக்கொள்ளாதிருக்கிறான்…
– by actions, these 2 are 2 extremes but intentions are the same. As long as my intention is good, I don’t have to worry about my actions but
21 மாம்சம் புசிக்கிறதும், மதுபானம் பண்ணுகிறதும், மற்றெதையாகிலும் செய்கிறதும், உன் சகோதரன் இடறுகிறதற்காவது, தவறுகிறதற்காவது பலவீனப்படுகிறதற்காவது ஏதுவாயிருந்தால், அவைகளில் ஒன்றையும் செய்யாமலிருப்பதே நன்மையாயிருக்கும்.

For the kingdom of God is not a matter of eating and drinking but of righteousness and peace and joy in the Holy Spirit. Let’s seek to pursue a righteousness life with the help of God, enjoy the peace of God by being in peace with God and spread the joy through his spirit.

The principle of what Paul is saying is that we are to live for God, what we do and don’t do should come out of a heart conviction and not because of rules and regulations given by others. What God has revealed to us as acceptable before him, we should be confident in.