I believe that the answer is as simple as understanding the words of the two thieves who were crucified with Christ! One thief mocked Christ and the other seems to have repented and accepted Christ as God! This accounting from St. Luke speaks nothing of baptism nor works.
Luke 23:39-43
New International Version (NIV)
39 One of the criminals who hung there hurled insults at him: “Aren’t you the Messiah? Save yourself and us!”(A)
40 But the other criminal rebuked him. “Don’t you fear God,” he said, “since you are under the same sentence? 41 We are punished justly, for we are getting what our deeds deserve. But this man has done nothing wrong.”(B)
42 Then he said, “Jesus, remember me when you come into your kingdom.[a]”(C)
43 Jesus answered him, “Truly I tell you, today you will be with me in paradise.”(D)