The lens of the cross

"The cross tells us that our biggest, deepest, and most abiding problem is to be found inside of us, not outside of us... People, locations, and the situations of life all influence what we think and what we do, but they are not determinative.
No, the most powerful life-complicating problem for us all is to be found deep inside of each one of us. It is the reason for the cross of Jesus Christ. It is the thing that the cross was ordained to defeat. It is the thing that distorts our thoughts, desires, emotions, choices, words, and actions. It is the universal human dilemma, the inescapable pathology. It is the one disease we all suffer from. It is the problem none of us has the wisdom or power to solve. What is it? Sin. It is the condition of heart that is the fundamental reason for a vast array of personal and interpersonal brokenness. The cross requires us to admit that we, too, have been infected with the virus and are people in desperate need of help. We have not just been afflicted with a fallen world and flawed people. No, we have all been infected with sin...

If what is broken inside of us could have been cured by a body of knowledge or a system of insights Jesus wouldn’t have needed to come and the cross would not have been necessary... For lasting change to take place in us, we need more than and system; we need a Redeemer. Only the grace of a Redeemer, who on the cross defeated our deepest problem, is able to rescue us from us and give us the power to live in brand new ways."

taken from an excellent article by Paul Tripp, The Ultimate Lens on Life (read the full thing here)