Here’s some essential, epic Charles Spurgeon, on Romans 6:14:
Sin is a domineering force.
A man cannot sin up to a fixed point and then say to sin, “Up to here shall you come, but no farther.” It is an imperious power and where it dwells it is hungry for the mastery. Just as our Lord, when He enters the soul, will never be content with a divided dominion, so is it with sin, it labors to bring our entire manhood under subjection.
Therefore we are compelled to strive daily against this ambitious principle. According to the working of the Spirit of God in us we wrestle against sin that it may not have dominion over us. It has unquestioned dominion over multitudes of human hearts and in some it has set up its horrid throne on high and keeps its seat with force of arms so that its empire is undisturbed. In others the throne is disputed, for conscience mutinies, but yet the tyrant is not dethroned. Over the whole world sin exercises a dreadful tyranny. It would hold us in the same bondage were it not for one who is stronger than sin, who has undertaken to deliver us out of its hand and will certainly perform the redeeming work.
Here is the charter of our liberty, the security of our safety—“Sin shall not have dominion over you.” It reigns over those who abide in unbelief, but it shall not have dominion over you, “because greater is He that is in you, than he that is in the world.” The whole world lies in the wicked one, but “you are not of the world” and therefore “sin shall not have do- minion over you.”
If we are distressed by the fear that sin will ultimately get the mastery over us, let us be comforted by our text. Holy jealousy leads us to fear that though we have for many years been enabled to maintain a spotless character before men, we may in some unguarded hour make shipwreck of faith and end our life voyage as castaways upon the rocks of shame. The flesh is frail and our strength is perfect weakness and therefore, we dread lest we should make some terrible fall and bring dishonor upon the holy name by which we are called. Under such feelings we may fly for comfort to the rich assurance of the text, “Sin shall not have dominion over you.”