"There Is One God And One Mediator Between God And Men, The Man Christ Jesus" 
1 Timothy (2:5)

Was Jesus God manifested in the flesh?

No, this belief is taken from (1 Timothy 3:16) which is a passage that is commonly misinterpreted. This passage is telling us that God was made manifest (made known/revealed) through Jesus, a man (Mark 15:39, John 8:40; Acts 2:22; Romans 5:15) having flesh and bone, who God received up to glory.

Jesus distinguishes the difference between the two and said:

(Luke 24:39)  Behold my hands and my feet, that it is I myself: handle me, and see; for a spirit hath not flesh and bones, as ye see me have.

(John 4:24)  God is a Spirit: and they that worship him (NOT THEY THAT WORSHIP ME!) must worship him (GODin spirit and in truth.