There are many illustrations of Trinity. However, since God is God and beyond our comprehension, our illustrations are not absolute and therefore prone to error. Some imagine the One God to be within their comprehension; My God, is the God of the Scripture, who is beyond my comprehension, but provides understanding to those who fear Him everyday.
1x1x1 = 1 is usually used to debunk the opposition of trinity: 1+1+1 = 3. However, what about 1x1x1x1x1x1 = 1? Neither is 1/3 appropriate, for when Jesus prayed "My God, My God" in Matthew 27:46, He was referring to the 1 God, not 1/3.
It cannot be allowed that because someone tries to "support" Doctrines of Christianity, we should keep quiet even if his "support" is erroneous by itself. However, we must know that the goal is to glorify God, not to win a debate.
Nevertheless, from the scripture we know, there is only one God, and we know, there IS God the Father, God the Son, and God the Holy Spirit. There are no three Gods, but One. And that the Father is not the Son, the Son is not the Holy Spirit and the Holy Spirit is not the Father. This is the Scripture, God's word. The rest, through faith, we leave it to God.