Joseph Smith taught that the Son is the Father, and the Father is the Son. This is seen in his change to Luke, chapter 10, verse 22, in the JST. See below for the changes he made to this one verse. Please note that the JST means “Joseph Smith Translation” of the KJV.
Luke 10:22 (JST) – Jesus is the Father and the Father is the Son
22 All things are delivered to me of my Father, and no man knoweth that the Son is the Father and that the Father is the Son but him to whom the Son will reveal it.
Versus
Luke 10:22 (KJV) – The Father and the Son are different persons
22 All things are delivered to me of my Father: and no man knoweth who the Son is, but the Father; and who the Father is, but the Son, and he to whom the Son will reveal him.
The change you see above is what false prophets do to the Biblical text. They change verses into a lie from Satan. Modalism is not a teaching from the Bible, but a manmade teaching. This is where Jesus is the Father, and the Father is the Son, as the Father was manifest as the Son while He was on earth. Only heretics believe this false doctrine. True Christians believe that the Father, Son, and Holy Spirit are three distinct persons, not the same, but manifest as one God. This is called the Trinity. Amen.
See also christvm.com. The leading website on reaching Mormons for Christ.