This is rather a misquoted verse,
Philippians 4:12-13 (NIV2011)
[SUP]12 [/SUP] I know what it is to be in need, and I know what it is to have plenty. I have learned the secret of being content in any and every situation, whether well fed or hungry, whether living in plenty or in want.
[SUP]13 [/SUP] I can do all this through him who gives me strength.
The "all this" actually refers to what Paul has experienced, instead of "everything at will".
The bottom line is,
Jude 1:4 (NIV2011)
[SUP]4 [/SUP] For certain individuals whose condemnation was written about long ago have secretly slipped in among you. They are ungodly people, who pervert the grace of our God into a license for immorality and deny Jesus Christ our only Sovereign and Lord.
It simply says that you still need to follow laws to act. Grace is to save you from where you fail, it's not for you to do your fleshly wills without limit. Though it boils down to which set of laws you are going to follow.
In a nutshell,
The sets of laws specified in a covenant somehow has the added effect.
Gentiles (it's all humans before the Jews) need to follow the "Law in Heart" which God gives us as our conscience and moral code.
Later on, Mosaic Law was given for the Jews to follow, it however by no means says that they no longer need to follow their conscience or moral code in heart to act. As Jesus pointed out, some laws Moses set so because their hearts are hard, that is, the set of laws in the form of conscience and moral code goes corrupted in their hearts. Still God will consider them righteous as long as they can abide by Mosaic Law to a said standard (with Moses as the accuser).
Even today if by bloodline or custom or religion you claim to be a Jew, you need to follow the Mosaic Law to act. As a Jew however you have the advantage of choosing to be a gentile. That is, under the circumstance that you failed to or choose not to follow Mosaic Law to act, then you are now no longer under the Old Covenant signed with Moses but rather under the covenant granted to the Gentiles.
Similarly, today we are all gentiles thus need to follow our conscience to act. Our conscience may be a corrupted one though. It is because our version of conscience is corrupted that there's no much hope there for us to abide by it fully. We will fail at some point which will lead to our death. We thus need to New Covenant. The New Covenant is to save us from the situation how we failed. It by no means says that we no longer need to act in accordance to our conscience and moral code (a corrupted copy though).
The confusion however comes from whether we as gentiles need to follow Mosaic Law mentioned in OT. The answer should be no. Mosaic Law is for the Jews to abide by. However, it is very possible that the core commandments are common and overlapping in all covenants. So most of the 10 commandments may be found in each and every covenants, including our New Covenant, as Jesus Christ put it,
Matthew 19:17-19 (NIV2011)
[SUP]17 [/SUP] “Why do you ask me about what is good?” Jesus replied. “There is only One who is good. If you want to enter life, keep the commandments.”
[SUP]18 [/SUP] “Which ones?” he inquired. Jesus replied, “ ‘You shall not murder, you shall not commit adultery, you shall not steal, you shall not give false testimony,
[SUP]19 [/SUP] honor your father and mother,’ and ‘love your neighbor as yourself.’”
The difference made in the New Covenant is not how you should obey them, but rather how you will be judged in the Judgment Day. To simply put, you still need to obey them yet you won't be judged by them. You need to obey them though you will be judged by your faith and your faith alone.