That they all may be one, as You, Father, are in Me, and I in You; that they also may be one in Us, that the world may believe that You sent Me. 22 And the glory which You gave Me I have given them, that they may be one just as We are one: 23 I in them, and You in Me; that they may be made perfect in one, and that the world may know that You have sent Me, and have loved them as You have loved Me.” (St. John 17: 21-23) These are the Words of Jesus Christ our Lord. Christ is praying this prayer to His Father in regard to us—we who are the believers of him. In particular, he mentions that he and his father are one, and just as they are one, so also, we are one with them. This might seem like a contradiction, that is, that the Trinity and mankind could be one. But from the beginning of time, man has always searched for how there could be “unity” within “diversity.” For the Christian, at least, that quest is a reality with the Holy Trinity.
Read more: https://stlukemission.org/sermons/oneness-in-diversity