The last part of the question was, how often should we do it? Well, in a church that has communion every Sunday, of course you might be doing it every Sunday if it's part of your communion service, or at least in our church. On Sunday morning, I normally will greet many of the brothers with a kiss. Not everyone. Often I'm reaching over, and all I can do is shake hands with someone because they're already seated, or because there's a lot of people I'm greeting.
And particularly, like I say, once they're seated, it would be almost expected to stand up if you're going to exchange kisses. So I think a handshake works well there. But usually when a brother is standing, I will greet them with a holy kiss in our church, or in another church where it's customary to offer the holy kiss. And I'd say whenever it feels comfortable. Join us in earnestly contending for the faith that was once for all delivered to the saints.