On the one hand, no one “gets” to heaven in that you can’t “earn your wings,” so to speak. The heresy of Pelagianism was condemned by Saint Augustine and the Church in the fifth century.
Basically, it was the teaching that there was no original sin, and therefore mankind did not need to be saved or redeemed and anyone could merit heaven on their own efforts and accomplishments.
Augustine opposed this error vehemently, and his teaching became the official teaching of the Catholic Church. He maintained that the sin of Adam and Eve (original sin) is in fact transmitted by human nature to every man and woman. Only the divine grace of God (which he called sanctifying or habitual grace) can justify a person by removing original sin and making them capable of receiving more divine grace. Sanctifying grace only comes through baptism (whether by water, blood, or desire) and it alone makes us children of God.
Heaven is not a reward but a gift from God. He does not owe us heaven and we do not deserve it, nor can we earn it. Out of pure love, God offers us heaven, and by his divine grace we can accept the gift or, because of free will, we can reject it. Augustine denied Pelagius’ claim that one could merit or earn their way to heaven.
On the contrary, without divine grace, Augustine said, it is impossible for man to perform good works. Actual grace is the divine grace given after the sanctifying grace of baptism. Actual grace empowers and enables us to do good works and have those works become efficacious. Augustine did not refute the necessity of good works (as would Luther), but he denied that works alone (as espoused by Pelagius) could save you.
Those who believe and regularly practice their faith trust in the gift of salvation, but they never presume it or take it for granted. Catholicism teaches that the Christian is never a spectator but is always a participant. Jesus commanded that we deny ourselves, take up our crosses and follow Him (Matthew 16:24).
If we each follow Him to Calvary by carrying our own cross, and are buried with Him, we shall also rise with Him and join Him in heaven. Not because we earned it, but because God’s grace is at work in us.