To accept Jesus’ invitation to come to Him – to be His disciple – is to take on an obligation. It is a freeing or liberating obligation, but an obligation nonetheless.
Since Jesus is Lord, those who have come to Him and live under his yoke (Matthew 11:30) have no freedom to behave in any other way than what the Jesus – as Lord (read: Master, boss) – declares. Again, the Christian is free from the bondage of sin (Romans 6:18) so that he or she is able to live/act/behave in an obedient-to-Jesus way (1 John 3:22). Issues of morality, purity, ethics, are all gathered under Christ’s yoke that He call His followers to take upon themselves.
“And He said to them all, ‘If any man would come after me, let him deny himself, take up his cross daily, and follow me. For whoever desires to save his life will lose it, but whoever loses his life for My sake will save it’.” (Luke 9:23-24)
adapted from Alistair Begg