In Matthew chapter 19 and Mark chapter 10 we read the statement: what God has joined together, let not man separate or divide asunder. While this certainly applies to marriage in the natural, there is another marital application. As the bride of Christ; born again believers are married to Jesus. We that have received Him are one Spirit with Him (see 1 Cor.6:17; Hebrews 2:11).
Every time believers are taught to do something in order to be something that they already are in Christ; their understanding is being separated from their union with Christ Hence man is separating what God; through the new birth has joined together. You that have received Him are joined together with Him. Protect this union through the knowledge of God and Jesus your Lord (see 2 Peter 1:2). You are His.