I listen to John Piper's 'Ask Pastor John' podcast every once in awhile and he defined sin in a way that I had never heard before. When you read it, it makes sense that this is sin, sinful, sinful acts.
Sin is...
the glory of God not honored,
the holiness of God not reverenced,
the greatness of God not admired,
the power of God not praised,
the truth of God not sought,
the wisdom of God not esteemed,
the beauty of God not treasured,
the goodness of God not savored,
the faithfulness of God not trusted,
the promises of God not believed,
the commandments of God not obeyed,
the justice of God not respected,
the wrath of God not feared,
the grace of God not cherished,
the presence of God not prized,
the person of God not loved.
"But whoever has doubts is condemned if they eat, because their eating is not from faith; and everything that does not come from faith is sin." Romans 14:23 NIV
"But if you have doubts about whether or not you should eat something, you are sinning if you go ahead and do it. For you are not following your convictions. If you do anything you believe is not right, you are sinning." - NLT
Another definition by John Piper: Sin is anything, any act or any emotion or attitude, that does not sprout from the soil of such confidence in the God of hope. "Whatever is not from faith is sin."
With all of this sin talk....here's faith defined according to John Piper.
Faith is confidence in God to work in the affairs of our lives so that only what is best for us happens to us. Unbelief is what displeases God in every sinful act. "Without faith, it is impossible to please God." Hebrews 11:6
And without faith, how can we experience joy and peace from God?
"Now may the God of hope fill you with all joy and peace in believing, so that you will abound in hope by the power of the Holy Spirit." Romans 15:13 NASB