Many worldly people, especially young people, are extremely naive about unity. They even think they can "make love" and make unity by their own power. They think they can make a marriage work without a commitment to the Lord, without the Church, and often without prayer. Most of these naive, worldly people are soon crushed in their broken relationships.
As brokenness and unfaithfulness become a pattern in their lives, they despair of love and unity and become cynical about even their possibility. Thus, when a crushed, broken worldly person meets true love and unity, they can't believe it. They deny it and wait for it to unmask. However, if this marriage, family, church, or community is truly in love and unity, the worldly person is strongly challenged to repent, forgive, and believe in Jesus Who will baptize them in the Spirit of unity (see Mk 1:8). If they accept the Lord's salvation, these broken, worldly people then have a new Pentecost where barriers against communication are broken down (see Acts 2:6ff). They are baptized in one Spirit into one body (1 Cor 12:13). They are of one mind and heart with their brothers and sisters in Christ (Acts 4:32). They begin to be one as Jesus and the Father are one (Jn 17:21).