Hebrews 7:25 (NKJV)
Therefore He is also able to save to the uttermost those who come to God through Him, since He always lives to make intercession for them.
There is no one so bad that he cannot be saved. He is able to the uttermost. But we have to come to God through Christ. How does Jesus save us? He represents us before God. That is the ultimate in intercessory prayer.