Psalms 2:11

Serve the Lord with fear That is, with reverence and an awful sense of his great and glorious majesty, rendering you careful and diligent to please him, and afraid to offend him. And rejoice Do not esteem his yoke your dishonour and grievance, but know that it is a greater glory and happiness to be the subjects of this King than to be the emperors of the greatest empire; and accordingly rejoice in it, and bless God for this inestimable grace and benefit; with trembling This is added to signify the quality of the joy to which he calls them and to distinguish it from that carnal and worldly rejoicing which is usually attended with security and presumption; and to warn them to take heed that they did not turn this grace of God into wantonness; but, on the contrary, work out their salvation with fear and trembling.