While Jesus' words indicate an expressed inability on the part of the unbeliever to come to Him without being "drawn," some may wonder why unbelievers should be called to repentance? In other words, if they can't come (unless they are drawn), why tell them to come?“No one can come to Me unless the Father who sent Me draws him; and I will raise him up on the last day.”(John 6:44)
Something to keep in mind is what is meant by "ability" as it relates to Jesus' words. In what way can't unbelievers come to Christ without being drawn? In thinking about this question, it might be easy to suggest that they can't come to Christ even if they wanted to. But such thinking doesn't correlate to how Scripture defines this "inability."
While this text doesn't express the full scope of the unbeliever's depravity, it does show us what is meant by "inability." The "not even able to do so" has everything to do with desire. That is, they can't please God because they don't want to please God. Why don't they want to please God? Because its in their nature as fallen sons of Adam. And as long as God refrains from extending grace to unbelievers (i.e. drawing them), they will never come to Him. After all, Christ says, "Without Me you can do nothing." (John 15:5)“Because the mind set on the flesh is hostile toward God; for it does not subject itself to the law of God, for it is not even able to do so, and those who are in the flesh cannot please God.” (Romans 8:7–8)
To illustrate this further, i'd like to provide some parallel examples. With regards to John 15:5, why would anyone rebuke others for doing evil if they aren't in Christ? Wouldn't they need to be in Christ to live righteously?
“So then it does not depend on the man who wills or the man who runs, but on God who has mercy.”(Romans 9:16)If it depends on God and not on man, then why would Paul rebuke man for their sinning against God? Even with the hardening of Pharaoh's heart, why would he be rebuked for something that God is doing?
Yet, the Scriptures declare that men are only capable of this when God has done a work in their hearts:“I call heaven and earth to witness against you today, that I have set before you life and death, the blessing and the curse. So choose life in order that you may live, you and your descendants,” (Deuteronomy 30:19)
“Moreover, I will give you a new heart and put a new spirit within you; and I will remove the heart of stone from your flesh and give you a heart of flesh. “I will put My Spirit within you and cause you to walk in My statutes, and you will be careful to observe My ordinances.” (Ezekiel 36:26–27)
So why rebuke man for things they are "unable" to overcome? Because rebuke is the means by which salvation is accomplished. Men will not come because they don't want to come. But they will want to come when God gives them a new heart and draws them through the preaching of the gospel. For that reason, we should be faithful to share the gospel with everyone since we don't know who's heart is being made new by the Spirit.