While other religions might view absolution as being granted by the religious establishment, or directly from the deity, Judaism sees things differently.
If one has sinned against G-d (for example by violating Shabbat), one can ask G-d for forgiveness. The great 12th century rabbi Maimonides wrote extensively on questions of repentence, and laid out a path for true absolution: confession, remorse, and the resolution not to repeat the sin.
While those are important for sins between one person and another, such as unkindness, untruth and the myriad ways we find to hurt each other, none of them matter without asking for the forgiveness of the injured party.
There are probably few things in this life that are more difficult than collecting one’s courage, going to a person one would rather avoid, and saying, “I have wronged you, please forgive me.”
Of course these words need to be backed up by the appropriate remorse, desire not to repeat the offence, etc. Just getting them out can be so hard.
There is no guarantee that the person will be willing to pardon the offence. But it is up to you to ask, and if you ask three times in all sincerity, you have fulfilled your obligation.
I can think of a few people whom I need to ask for forgiveness this season. How about you?