In your theology, please don’t place too much emphasis on the thief on the cross.
He may be the standard for some who are saved, but he is not the standard for most. And he will most likely not be your standard. While it is true that God saves some repentant sinners at the end of their lives (before they are able to be baptized, exercise their gifts, and bear fruit) this is not the norm. Nor should it be set as an ideal.
God saves most sinners long before he takes them into paradise.
He saves them while they still have time: time to live; time to grow in their faith, in their holiness, in their usefulness. He invites them to identify themselves with Jesus’ death through baptism. He invites them to join a body of believers to be built up and build others up. He invites them to remember the finished work of Jesus by regularly eating the Lord’s Supper. He invites them to learn to pray: to adore, to confess, to thank, to petition, to intercede. He invites them to validate their faith by their works. He invites them to endure trials. He invites them to resist the sinful patterns that used to trip them up. He invites them to share the gospel with their neighbors. He invites them to love their friends and their enemies. He invites them to this and so much more.
The thief on the cross was not able to do any of these things.
Yes, the thief on the cross “made it in” but he is not meant to be the pattern for how others are meant to live as Christians- or even when they are to be saved. If you are waiting to convert at the last moment, the Bible says, “See… now is the day of salvation!” (2 Corinthians 6:2 CSB).
(And I believe that if the thief had been taken down from the cross after Jesus pardoned him, having somehow been enabled to live longer than a week, he would have pursued baptism, fellowship, the breaking of bread with other believers, prayer, evangelism, and service.)
If you are hoping that your one-time profession of faith (or your potential deathbed confession) will get you into heaven, you may be pleasantly surprised. But you will have missed out on all the good (though often challenging) things the Lord had for you in this life.
Please don’t model your life after the thief on the cross. Live like Peter or John; Mary or Martha; Paul or Timothy; Prisca or Phoebe. Live like Jesus: always doing works motivated by faith until asked to lay your life down. The author of Hebrews encourages us to “lay aside every hindrance and the sin that so easily ensnares us. Let us run with endurance the race that lies before us, keeping our eyes on Jesus, the pioneer and perfecter of our faith” (Hebrews 12:1b-2a).
Please don’t use God’s offer of salvation as a ticket out of hell. Treat it like a job offer with amazing retirement benefits.
And don’t forget what Jesus said, “Look, I am coming soon, and my reward is with me to repay each person according to his work” (Revelation 22:12).
If you are unfamiliar with the story of the thief on the cross, please read the brief account in Luke 23:32-43. (You may find it helpful to read the rest of chapter 23 for context.)