You have probably read that chapter more than once. Read it again with chapter (5) and come back to your thread and explain in your own words what you have understood those chapters to say.
The baptism into Jesus Christ and His death in relationship to sin and grace is something every believer needs to understand. There have been all kinds of problems arise from not knowing the difference between positional truth and experiencial truth. You, as a new believer, have the opportunity to understand who you are in Christ positionally, and how God works that position into your experience so that you can live in the truth that you know.
Example: You have been baptised into Jesus Christ and His death because of the cross and that is positionally true, even though it has not become your experience yet. Let's say you react to certain people when they are around you. You may have a very good reason but God wants to get rid of that reactionary spirit and give you peace instead. So God ordains certain details for your life that works death in you through the cross, to crucify you experiencially so that you don't react toward those people. This is part of the process of (Col 1:20-22). Without God working death (or the cross) into your experience, you would never be free from that reactionary spirit. God experientially crucifies that spirit and gives you the fruit of the Spirit which is peace (Gal 5:22). God uses the death that you have been baptised unto, to experiencially give you victory over those things that you know are from the old sin nature. Now Christ, as our peace, can be revealed in us, as life to others (Eph 2:14-18).