Not to second guess this preist but I say penance is very important.
This is from
newadvent.org:
Necessity
The Council of Trent expressly declares (Sess. XIV, c.i) that penance was at all times necessary for the remission of grievous sin. Theologians have questioned whether this necessity obtains in virtue of the positive command of God or independently of such positive precept. The weight of authority is in favour of the latter opinion; moreover, theologians state that in the present order of Divine Providence God Himself cannot forgive sins, if there be no real repentance (St. Thomas, III:86:2; Cajetan, ibid.; Palmieri, op. cit., thesis VII). In the Old Law (Ezech., xviii, 24) life is denied to the man who does iniquity; even “his justices which he has done, shall not be remembered”; and Christ restates the doctrine of the Old Testament, saying (Luke, xiii, 5): “except you do penance, you shall all likewise perish.” In the New Law, therefore, repentance is as necessary as it was in the Old, repentance that includes reformation of life, grief for sin, and willingness to perform satisfaction. In the Christian Dispensation this act of repentance has been subjected by Christ to the judgment and jurisdiction of His Church, whensoever there is question of sin committed after the reception of Baptism (Council of Trent, sess. XIV, c. i), and the Church acting in the name of Christ not only declares that sins are forgiven, but actually and judicially forgives them, if the sinner already repentant subjects his sins to the “power of the keys”, and is willing to make fitting satisfaction for the wrong he has done.
newadvent.org/cathen/11618b.htm