One discussion that often comes up is: do I need to regularly attend a local church? Another subset of this question is: do I need to become a church member?
Often times we are told there was no portrait of church membership in Scripture. I will admit some churches today may practice membership as a form of self righteousness justifying their own self worth as a church by how many numbers they can pad into their roles. Yet I would maintain church membership is important and 100% faithful with Biblical practices--when it is not abused. Membership is basically mutually acknowledged commitment in a local body and agreement with the local elders/under-shepherds that you are under them and that they will watch over your soul according to the Biblical proscription.
I'll start with a statement and then ask a series of questions.
If a Christian cannot submit to under-shepherds anywhere or in any form, he cannot substantiate the claim he is truly submitting to the Shepherd.
Can we really show commitment to a local expression of God's body if we bounce around from church to church? We are supposed to have elders exercising oversight over us (1 Pet. 5:2), we are supposed to have people watching over our souls so that they can give an account to God for us (Heb. 13:17) can that happen when weekly, monthly or yearly I switch from church to church? Can watch over my soul really happen if I don't make it a habit to gather with at least one consistent group of believers? Christian growth takes years and decades, can others answer in watch over me if I exit in monthly patterns? Can I really obey and submit to a particular group of leaders (Heb. 13:17) if I make a habit not to have one particular place of worship?
How can you place yourself under elders teaching and preaching if you don't even go regularly to the same church? How can they watch how you interact with the family of God if you don't gather regularly within one family context? If each week you are under a new set of teacher and elders, how can anyone offer you spiritual care and oversight? How can you claim to obey and submit (Heb. 13:17) if you are not regular, habitual and even staying through the long haul.
How can under-shepherds watch you grow up in faith and doctrine protected from false doctrine that abounds out there (Eph. 4:14) when you freely bounce around to places with all manner of teaching? How can they love you and knit you into Christ's body and a local expression of it, and see that you are properly fitted into the body (Eph. 4:13, 15,16), when they don't even go to the same local body as you? When you cannot knit yourself in with anyone or under anyone for a regular, consistent and habitual period of time can you really claim to manifest the spiritual maturity demonstrated by one who is knit to Christ?
Can you really claim the love of God is manifest in you, if you cannot be patient, long-suffering, loving and keep no records of wrongs with fellow believers inside a single expression of Christ's body?
Commitment to the local church is vital for your spiritual growth and development. It is part of your spiritual life. If you are being knitted into Christ's body and you are growing up in your faith and in love, you will grow in your commitment and expressions of love within a particular local expression of Christ's body.