Fellowship and a sense of community is not only a gift but it is vital necessity for a healthy Christian walk. No man is an island and we were not meant to go it alone! The journey becomes easier or tougher depending on the quality of fellowship we experience and surround ourselves with. It can determine whether the journey is an up hill depressing struggle, or whether we feel the presence of God made real to us every step of the way, through the people we choose to have around, during the best or worst of times.
MATTHEW 18 VERSE 20
“For wherever two or three are gathered in my name, there I am in the midst of them.”
When fellowship comes, there is the opportunity for intimacy with a selected few, drawn together through the common ground, of enjoying humanity and the Grace of God. Here is somewhere safe to be yourself, and be understood. Often this is the forum where you gain exposure to the love of God, and a true picture of yourself through friends who see you through God’s eyes. It is also the place where through different people, we catch precious glimpses of the heart, character and person of The Lord Jesus Christ. It can be likened to finding the treasure at the end of a challenging treasure hunt. Through friends we experience God in a more personnel way and he becomes more real to us. Sharing here is built on developed trust, and can bring clarity to the most complex of issues. The burden of carrying the most painful circumstances can be lifted and made easier through not having to walk alone. When walking alone you only have a piece of the puzzle, but a shared perspective gives a fuller picture.
Testimonies and stories told during times of fellowship can be a source of great Strength. Things often seem worse when you think that the challenge is unique to you. It always helps to know that others can relate to your particular struggles, and are still alive to tell the tale! It is encouraging to know that the God who delivered them, is your God and will do mighty things to deliver you also.
MATTHEW 18 VERSE 19
“If two of you on earth agree about whatever they may ask, it will come to pass and be done for them by my father in heaven.”
The unity that comes through the sense of community is powerful. The prayers that originate from this can effectively bring about changes that perhaps would not necessarily be seen otherwise. This applies also to worship which is best experienced in company. The presence of The Lord felt during these times is so tangible that you feel that you could literally touch the hem of his garment!

I am so glad that you found a great Christian community. God designed us to need each other.
It’s amazing to me how God grows Christian communities through various seasons. Everything you say is so true, and this reminds me of John Donne’s Meditation, which I’m guessing from your title that you’ve read (since the phrase “no man is an island” came from Meditation 17, and his sermon/meditation is about the exact same topic). It’s one of my personal favorites when I’m teaching British literature.