6 not with eyeservice, as men-pleasers, but as bondservants of Christ, doing the will of God from the heart,
A Christian in service of others does not do the minimum but the maximum.
not with eyeservice,
A Christian does his work without the requirement to keep his eye on his boss. He does not work hard only when his master is looking but even when he is not watching. He does his work with integrity regardless of who is watching. Those in authority over him do not need to constantly watch over him.
Slaves were not to keep their eyes on what men thought but about what God thought about their service. Christians do not do what they do to please people but God Himself.
but as bondservants of Christ,
Slaves were to operate like slaves of Christ, not currying favor with men but God, their ultimate allegiance to Christ.
doing the will of God
The unseen Master expects faithful service from His personal servants even when people are not watching them.
from the heart [soul],
The idea here is wholeheartedly.
Our service revolves around allegiance to Christ.
Christians do the best job whether anyone is watching or not. They will do their finest whether they are treated right or not, whether they are appreciated or not. Those things are incidental to pleasing God with what he does.