Jesus Christ is the same yesterday, today, and forever. (Hebrews 13:8)
There has been and will always be an unchanging foundation. And that foundation is Christ. As the old hymn says, "On Christ the solid rock I stand, all other ground is sinking sand." The nature of man from the fall has been a sinful nature. The nature of Christ has always been perfectly righteous and filled with mercy and grace. Therefore sin has always been sin and Christ's righteousness has always been righteous. Both are unchanging. We are sinners who require the unchanging righteousness of Christ. Sin may be more prevalent than any time in recent history, but it remains the same sin that has been in every man, woman and child from the fall of Adam. Sin hasn't changed and Christ hasn't changed. His standard, ways and calling are unchanging. It takes no more or nor less to overcome sin today than it did any time throughout the history of man. Christ will never be the one in need of change; it has always been and will always be mankind in need of change.