Whenever I have seen denominations which preached that we must follow ecclesiastical laws as well as accept Christ or we aren't really saved, I have soon come to the realization that the 'laws' which they really emphasize are those which benefit the heirarchy of that denomination. They may pay lipservice to not committing murder, adultery, theft, etc., but they insist that if a person wants to be truly saved, he has to coax others into leaving their denominations and joining that particular denomination. IOW, it's a pyramid scheme with salvation being used as the impetus.
The reality is that in order for us to live lives that are in accordance with what God wants of us, we must first place our faith in the sacrifice of Jesus Christ as the sole means of cleansing us of our sins and removing those sins from us. After accepting this gift of salvation, we must again place our faith in God's ability to remake us into the people who can carry out the work that he wants of us:
So I say, live by the Spirit, and you will not gratify the desires of the sinful nature. For the sinful nature desires what is contrary to the Spirit, and the Spirit what is contrary to the sinful nature. They are in conflict with each other, so that you do not do what you want. But if you are led by the Spirit, you are not under law.
The acts of the sinful nature are obvious: sexual immorality, impurity and debauchery; idolatry and witchcraft; hatred, discord, jealousy, fits of rage, selfish ambition, dissensions, factions and envy; drunkenness, orgies, and the like. I warn you, as I did before, that those who live like this will not inherit the kingdom of God.
But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness and self-control. Against such things there is no law. Those who belong to Christ Jesus have crucified the sinful nature with its passions and desires. Since we live by the Spirit, let us keep in step with the Spirit. let us not become conceited, provoking and envying each other. (Galatians 5:16-26,NIV)
The acts of the sinful nature are the origin of every sinful act which has ever been committed. They are also at the very core of the nature we are all born with. Some are suppressed as we grow up due to familial and societal pressures, but they're still there. And no righteous act can be performed by using the motivations listed here. Just as a poisoned tree cannot bear good fruit, an action using these motivations as its reason for being cannot be seen as righteous.
But since they are at the very core of our being, we can't simply brush them aside. They are ourselves, and are as much a part of us as our eye color and our ethnicity. It would be easier for a leopard to exchange his spots for the stripes of a tiger than it would be for us to subdue these motivations. We need outside help. That's why in the first paragraph of this passage it's the Spirit who is battling our sinful nature, not we ourselves doing battle with it.
But subduing our original nature is not the only thing that the Spirit does. He implants within us a new nature, one which has 'the fruit of the Spirit' at its core. It is through the influence of these 'fruit' on us that we become capable of saying and doing the words and actions which God wants of us. Just as 'the acts of the sinful nature' can be seen as the origin of every sinful act, 'the fruit of the Spirit' can be seen as the origin of every righteous act. That's why the words immediately following their listing are, "Against such things there is no law." When these 'fruit' dictate our words and actions, then those words and actions will be 'in synch' with what God wants of us.
We need to remember this saying: "He did all the right things, but for all the wrong reasons." Certain actions can superficially be seen as righteous. But whether or not that is truly the case depends on what the impetus was which preceded the action. Was it a desire to make points with God, and thus earn stars in our crowns? Then the impetus was selfish ambition, an act of the sinful nature. Was the impetus a desire to show kindness and compassion toward others? Then the impetus was the fruit of the Spirit. In order for the action to be seen as righteous, the impetus must also be righteous.
But can this be accomplished if we are frightened? Can we adopt this nature if we are afraid that our actions from one minute to the next will either keep us safe, or condemn us to hell? No, it cannot. If we're afraid that we will condemn ourselves from one moment to the next via our own weaknesses, our sole concentration will be on our own welfare, rather than the welfare of those around us. It is only when confidence in our salvation is assured through accepting it as a gift offered to us freely because of God's infinite mercy that we can be remolded into a being with the new nature that God wants us to have, and to manifest toward others.