You mean it's not obvious that abortion is murder? You needed to be told that?
Jesus was not a social revolutionary. He did not come to "fix" society or address all of its problems. Slavery is incompatible with Biblical principles - that's why Christians were generally supportive of ending slavery here in America.
God made it clear in both the OT and in the NT through the words of Paul.
Why does Jesus have to say all this? These things were not his priority - saving human souls was. Here:
"And God said, Let there be light; and there was light. And God saw that the light was good; and God separated the light from the darkness. And God called the light Day, and the darkness he called Night. And there was evening and there was morning, the first day." Genesis 1:3-5
Which part of that is unclear?
Your questions, understandable as they are, reveal that you do not have even the slightest understanding of Christ's mission on earth; as well, they imply that you've not read very closely the book you are choosing to criticize. As a matter of fact, Christ did have "better" things to do - saving humanity from the consequences of its sin. Christ was not a social revolutionary; He did not come here to correct society's ills with a neat listing of new commandments. He came here to show us a better way of living, and to offer us the gift of eternal life - all of us. A careful examination of the NT clearly reveals principles that are to guide us in making decisions about abortion, slavery, etc. Christ did not have to address every social/personal problem in order for us to understand how to address them - behaviors inconsistent with the principles put forth in the Bible ought not be done. Period.
For those of us who have spent years studying the Bible, we find that it can be quite clear. That doesn't mean that there aren't points of confusion, but that clarity can be found in the Bible - provided one is being led by the Holy Spirit. Non-believers reading without God's guidance may very well be confused by certain things that make perfect sense to believers.

