Concerning the thief on the cross, I offer these things to your thoughts.
(1) He was saved to teach sinners not to despair, so another was damned to teach them not to presume. A pardon is something given to one upon the gallows, but whoso trusts to that, the rope may be his hire.
(2) It is an example without a promise. Here it is an example of late repentance, but where is there a promise of late repentance? Oh! let not his late and sudden conversion be to you a temptation. Not examples but promises are foundations for faith to rest on. He that walks by an example of mercy without a precept to guide him, walks but by a dark lantern that will deceive him. Young man, remember that examples of mercy increase wrath when the heart is not bettered by them.
(3) This was a rare miracle of mercy, with the glory whereof Christ did honour the ignominy of the cross.
The sermon on the cross was the first that this man ever heard Christ preach, and Christ’s prayer on the cross was the first that he ever heard Christ make. He knew not Christ till he met Him on the cross, which proved to him a happy meeting.
But this is not His ordinary way of bringing souls to glory, and therefore O young man, let not the thief’s late conversion, prove a temptation or an occasion of delaying your repentance, and trifling away your days in vanity and folly.
From: Thomas Brooks’ Works.