Acts 2:25-36 Jesus was the Messiah; Who is David?  1 & 2 Samuel.  Please, please, please read your Bible the inerrant (without any errors) divinely inspired (God gave the writers the words to write) TRUTH.  You have to read the whole book to understand, the old testament is fulfilled in the new testament.

Here are a few Bible reading helps: YouVerson Bible app, Blue Letter Bible app, Biblegateway.com.

Blessings!