It does not matter how much prophecy we know, whether we can recite from memory large portions of Scripture, or know perfectly every doctrine's technicalities (I Corinthians 13:1-3). In terms of judgment, what matters is whether we are striving to live what we know to be the way God lives because it is how those in His Kingdom will live. His way is the way of love, and love is something we do.
Humanly, the opposite of love is hate. This is because we judge things largely according to the senses. Love, therefore, is a strong feeling for a person or thing; hate is a strong feeling against. However, this definition is not biblical. Biblically, the opposite of love is sin. Like love, sin is also something we do. According to I John 5:3, love is keeping God's commandments, and sin, then, is the breaking of His commandments. Though feeling is certainly involved in biblical love, the will of God and truth play a far larger part.
Seriously consider this: If we sin, then biblically, we do not love God, our fellow man, or for that matter, ourselves, because sinning means we have taken steps toward committing spiritual suicide! If we do this, it also means that we do not appreciate that God has given us life and has given His life so that we can claim His awesome promise of living eternally with Him.
Stripped of all possible nuances that might affect God's judgment, this is the stark reality of what faces us once God has opened our eyes and revealed His purpose to us. It brings to the fore that, if we love what He has revealed, then we must hate sin because it destroys everything God's wonderful revelation stands for.