i am confused by his claim because it says in John 1:18
"No one has ever seen God, but God the One and Only, who is at the Father's side, has made him known."
And again in John 6:46
"No one has seen the Father except the one [Jesus] who is from God; only he has seen the Father."
If you believe the words of Jesus, than Joseph Smith could not have seen God.
The passage in John helps to understand the context a little-
John: 35- 40
Then Jesus declared, "I am the bread of life. He who comes to me will never go hungry, and he who believes in me will never be thirsty. But as I told you, you have seen me and still you do not believe. All that the Father gives me will come to me, and whoever comes to me I will never drive away.
For I have come down from heaven not to do my will but to do the will of him who sent me. And this is the will of him who sent me, that I shall lose none of all that he has given me, but raise them up at the last day. For my Father's will is that everyone who looks to the Son and believes in him shall have eternal life, and I will raise him up at the last day."