Some Church Fathers tried to reconstruct the pronunciation for the Tetragrammaton, but the fact is that the LXX, the Greek New Testament, Liturgy and all the quotations thereof use the translations "Lord" and "God" instead. Knowing a name is knowing a reality, but we know (and own) God's essence. The Name was pronounced even in Judaism only in a limited form (in particular, the High Priest in the Holy of holies). I know that Jehovah's Witnesses use the reading "Jehovah" for the Holy Name using specific quotes, such as
O magnify Jehovah with me, you people, and let us exalt his name together (Psalm 34:3)
to say that pronouncing the name is necessary to fulfill God's will. The truth is that:
1) None, even the church fathers, know/knew the real pronounciation of God's Name, the Tetragrammaton.
2) The Name of God, for Christians, is 'Father'.
3) When we are baptised in God's name, we are baptised "in the name of the Father, of the Son and of the Holy Spirit", which has been correctly named the Holy Trinity by the Church. That's the true Name of God we have been given to pray and praise Him.
4) The New Testament, despite all claims from JWs, has never used the Tetragrammaton, and so did the LXX whence the NT quotations come from.
Now, the question is: can God's name be pronounced? I would say: yes and no. Yes: when we need to explain its meaning, for example when reading God's name in Exodus 3:14. No: when in ordinary life we have to invoke or name Him, because we have plenty of other useful titles for YHWH such as Lord, God, Father, Almighty, Most High, and Holy Trinity. Personally, if I am to name God as in the first case, I embrace no official pronunciation and adopt a spelling Yod-He-Waw-He which serves correctly for its purpose. Our salvation isn't - as JWs claim - dependent on our invoking of God with the name he adopted to reveal to Moses, but on our faith in our Lord Jesus Christ and in the church He built 2000 years ago.
In Christ, Alex