Ephesians 4:3-6 tells us we are one in the Spirit with one body (the church), one Spirit, one hope, one Lord, one baptism, one faith, you get the picture… We are to be one in the same Spirit that dwells inside each one of us whether we are Baptist, Pentecostal, Lutheran, Calvinist, pre-trib, post-trib, or however you tend to divide God’s kingdom.
But in studying Theology, we find differences of opinion in Pneumatology, Ecclesiology, Eschatology, etc. And we find it easy to major on the minors. These things can take our eyes off the big picture- GOD. In 1 Corinthians 1:10-13, Paul wonders about the divisions in the Corinthian church (“‘I am of Paul’ and ‘I am of Apollos’ and ‘I am of Cephas'”). Just like in our churches today, its easy to get puffed up over the way we do things in comparison to others (Our worship team is better than yours neener neener). If we actually did “test the Spirits” we might find we’re more the same than we would care to admit.