The point being discussed and to which you are responding is not how Lincoln felt about slavery. His hatred of the institution is well known. The point being discussed is whether he believed that the principles of freedom articulated in the Declaration of Independence were meant to apply to slavery, and therefore abolish it.
No knowledgeable and rational man could conclude that the Declaration was intended to apply to slaves. It is simply too great a disconnect to believe that the people who wrote and signed it could intend such a thing while at the same time keeping slaves themselves.
It is too great a stretch of credibility to believe such a thing, and Lincoln was not a fool. Now he may very well have believed that the principles articulated in the Declaration OUGHT to apply to slaves, but it is self deceit to believe what you think OUGHT be the law *IS* the law when it clearly is not.
As a politician of his times in the 1850s, Lincoln's expressed views were not dissimilar from those of other "moderate" Republicans -- he did not believe in abolishing slavery in the South, but did want it restricted from the western territories, and absolutely disagreed with interpretations of the Supreme Court's 1857 Dred Scott decision which suggested the Constitution required slavery to be lawful in every state!
As to whether Lincoln considered our Declaration of Independence the source-authority for abolitionism, I'd much doubt that.
The reason is that most ardent abolitionists took their beliefs directly from their understandings of the Bible's views on slavery, beginning with God's leading the Israelites out of Egypt.
Is that clear enough for you?