There are various ways by which some churches express their exclusivity. Some are obvious, but some are more subtle. like placing conditions on membership, or on your suitability to take the “emblems” (bread and wine) (“sacraments”).
It’s apparently not enough to be a member of Christ, you have to sign up to certain conditions which include financial obligations in the form of a contract.
Then to take the bread and wine you have to “love Jesus”. Too bad if you’re having a bad day and are feeling low and unworthy, or have just come into the church on an impulse of repentance, you might feel inclined then to give the whole thing a miss. [some people may be struggling with the sense of their own authenticity in Christ, and “conditions” such as whether or not they “love the Lord”, become interpreted as an excluding factor.]
And even the sermon can present exclusivity in the form of preaching holiness in such an Old Testament way as to increase the gap between you and God, instead of drawing you nearer.* “We all now with unveiled faces behold the glory of the Lord…” springs to mind, not hiding and distancing ourselves from the glory of God’s face. 2 Cor 3-18
[*This seems to be an example of going backwards theologically, assigning higher authority to an old covenant reference than to a new covenant reference.]