Romans 14 shows that observing the Sabbath is a matter of conscience, not universal Christian obligation; liberty must be exercised in love

Romans 14 addresses disputes over days (likely including the Sabbath) and food. The "weak" in faith are those with more restrictive consciences — not lesser Christians, simply more cautious. Paul's verdict: each person should be "fully convinced in his own mind" and act toward the Lord. The one who esteeming one day better than another and the one who treats all days alike are both accepted by God. Colossians also shows Paul rebuking the church for being bound by observance of days and weeks (which would include the Sabbath). Mike also treats the liberty/love tension: those with freedom should not flaunt it in front of those who are bound — love governs the use of liberty.