Andres
Is skipping/missing church for extended periods of time grounds for church discipline?
Biblically, the best answer is it could be.
We live in a generation, not unlike others, where the idea of any commitment beyond one's self is almost a shock.
Church attendance is viewed through the self-centered prism of personal choice, without any reference to duty to God or neighbor, let alone to the covenant community of believers.
So we have a generation of people who think they attend church without having any real commitment while doing so, and in a short while find something they do not like, or some person, and then they "hop" somewhere else or drop out.
In this, there is no consideration to a God who has saved you, commanded you to live by the Lordship of Christ, and according to His Word.
So the person who does not attend does not:
1) hear the Word taught authoritatively
2) take the sacraments
3) serve the covenant community with gifts and talents God has given
4) pray for visible church
5) tithe
6) worship God corporately
7) witness with His life as being in the Body of Christ
These are very, very serious things when one understands them biblically.
Living one's life apart from the visible Body of Christ is a part of denying Christ with your life. It is not "normal" for a believer. It is something for a believer to be ashamed of and to repent of. One that will bring God's chastisement on the life of the disobedient believer.
It's almost like a fish outside of water- it can survive a short while outside, but is very focused upon getting back in because it is natural and the only place it can really survive.
Someone who is able, but does not associate with Christ's Body is living a disorderly life pattern, one that would likely mean they ought refrain from taking the Lord's Supper until they have established themselves again in substantive fellowship.
This understanding all comes from a "high" view of the church- it's not merely a voluntary, conditional association of consenting adults- it is the Body of Christ. Denying that visibly is to deny Christ's Body.
Fellowship with the Body of Christ is not conditioned on one's evaluation of perfection of the Body, or even liking everyone in it, or feeling personally fulfilled at every moment. It's about more than that- it's about your duty to God, to the household of faith whom God has appointed for you, and about that witness before the world with your life.
To live apart from that, as a lifestyle, is a disorderly life pattern for a believer.
A disorderly life pattern requires discipline.
But remember, there are many forms of "discipline"- formal and informal, and of course there are valid reasons for absence- so we understand we are describing willful, disobedient absence- whether by carelessness, ignorance, avoidance or direct disobedience.
It's also somewhat subjective to determine "extended"- but even one Lord's Day of failing this is grounds for self discipline.
Probably one of most difficult biblical truths is that when a person professes to be a believer, but then shows no interest in His Body over an extended time, no interest at all- excuses maybe, guilt maybe, but nothing that provokes visible association-
It undermines the assurance for salvation of that person- and tends, not with absolute certainty, but tends to show they never really were a believer in the first place.
One way I have seen this recognized is with Deacon follow up with any member who misses more than 4 Lord's Day worship services in a row. This is done initially under a genuine pretense of, "Is everything okay? Is there anything we can do to help?" And, of course, allowing for many reasons and circumstances where someone might be absent for extended periods.
But this kind of accountability goes a long way toward binding covenant community together in caring.