Last time I wrote about explaining sin as poor choices. I said that this can be a good way to explain to your friend why he has the problems he does. So far, so good. But you still need to be careful. There are many ways that you can (will!) be misunderstood. Your friend may understand 'problems' in a way that will not be helpful. He may very well be thinking only of symptoms instead of the real issues. So, 'problems' can be understood in terms of things like marriage, job, kids, health and the like. Those certainly are problems, but you'll need to help your friend see that these are not the real issues of his life, the root problems that are the source of all that troubles him. If his life is going to be fixed he will need to focus on and deal with the root issues.
This is a good place for me to insert this thought. The way that we explain the Gospel to people has a great affect on their lives later. The goal isn't simply to get someone to say 'Yes' to Jesus so that they can end up in heaven. The goal is to see the Spirit create a disciple who will follow Jesus wholeheartedly and, as one result among many, experience great healing in his life. For this to happen you'll want to be very clear in explaining the Gospel. A bad foundation will result in an unsafe house, one that may not weather the floods and storms of life. Part of a careful explanation will include identifying and then dealing with root issues from which the problems of life come. These days, this will probably mean that explaining the Gospel will be a longer term project than what many have thought.
Now, I want to mention three problems that the Scriptures label as root issues that Jesus has come to deal with. The first is one that we are most familiar with, especially when it comes to thinking about presenting the Gospel to others. It's the issue of guilt. We are guilty before God. Another, less familiar root issue is powerlessness. Apart from Jesus, people are powerless to deal with life. The last of the three is shame. We were made to enjoy the status of being honored but instead we have fallen into the status of being shamed. Next time I'll begin to explain these.