The servant

 “Not everyone who says to Me, ‘Lord, Lord,’ shall enter the kingdom of heaven, but he who does the will of My Father in heaven." Matthew 7.21

The service of a servant is not limited only to some miraculous deeds in the name of Jesus. For what good is to perform miracles but do not obey the Word of God?
What really matters is not to do but to be.
Nobody is a servant by half. Either he is a servant in full or he is not.

Limited by the heart

"You are not restricted by us, but you are restricted by your own affections." 2 Corinthians 6.12

Most people have been limited by the feelings of the deceiving heart. Faith gets stuck in time and gets old...
That is why one needs to be born of the Spirit and become a new creature. A spiritual creature who does not walk by visible things, but by the invisible, which are eternal.