The problem with your gospel is you make justification contingent on actually being righteous in behavior - what you call 'holiness'. If justification is determined solely on your holy behavior you will never have the declaration of right standing with God that you need to get into the kingdom of God, because you are not always holy in behavior.
Born again people know this. That's why they are born again. They came to the end of themselves knowing they can't always live up to the righteous standard of behavior required by God for him to declare them righteous. And so, like the tax collector in Luke 18:13, they have cast themselves on God's mercy, openly confessing their unrighteousness, and God in his mercy has forgiven them and given them a declaration of right standing with him as a free gift of his grace.
You can't be born again until you honestly realize you can't get from here to there on the merit of your righteous behavior because you're not always righteous in behavior. The guilt of your unrighteous behavior doesn't go away just because you determine not to continue in that unrighteousness. It's always there on your record as a matter of historical fact.
God is just. The just and lawful penalty for sin must be administered. Born again people know this and believe God's word that Jesus absorbed that penalty into himself in their place on the cross and that he will forgive the guilt of their unrighteousness and make them legally righteous in his sight as a free gift of his grace if they'll believe and trust in that grace. And that he also gives the Holy Spirit to transform them and give them power over the sin that condemned them. And as children of God, they learn to use that power as they grow and mature in knowledge.
You can only get from here to there by the mercy of God's forgiveness which wipes away the unrighteousness that keeps you distant from him and unable to enter the kingdom. Your record of unrighteousness will always stand in the way until it is forgiven by God. You receive that forgiveness by having faith in his word that he will forgive you through the forgiveness he has made available through the blood sacrifice of Jesus. Sin is atoned for through blood, because the just penalty for the sin of mankind is death. You can either pay that penalty yourself and die for your own sins or accept God's free offer to let Jesus' death on the cross be the just payment for your sins. Born again people have chosen the latter.