Why can't our righteousness save us?

The biblical reality is that human righteousness, regardless of how morally upright one may believe themselves to be, falls short of God's glory due to the pervasive nature of sin. Romans 3:10 confirms that 'there is none righteous, no, not one.' This means that our efforts to be good or to earn God's favor are rendered ineffective because our works are marred by sin. Only by receiving and donning the righteousness of Christ can we be declared righteous and acceptable to God. His perfect life and sacrificial death fulfill the legal requirements of righteousness, allowing us access to the Father.