A great conversation starter to talk to JW’s is “Who Raised Jesus from the dead?”

30  But God raised him up from the dead, Acts 13:30 (NWT)

The New Word Translation confirms God raised Jesus from the dead, now ask them to look at the next scriptures in their Bible

19  Jesus replied to them: “Tear down this temple, and in three days I will raise it up.”l 20  The Jews then said: “This temple was built in 46 years, and will you raise it up in three days?” 21  But he was talking about the temple of his body.m 22  When, though, he was raised up from the dead, his disciples recalled that he used to say this,n and they believed the scripture and what Jesus had spoken. John 2:19-22 (NWT)

The NWT clearly documents that Jesus said he would raise himself from the dead, when I discussed this with JW’s they understood Jesus was declaring himself to be God. If they truly are honest and believe their scriptures, Jesus declares he is God in their own Bible

Now the question about the Trinity will come up and this is where the conversation will probably go off the rails, try to keep them on the path, lets look at the next scripture in their Bible

11  If, now, the spirit of him who raised up Jesus from the dead dwells in you, the one who raised up Christ Jesus from the deadp will also make your mortal bodies aliveq through his spirit that resides in you. Romans 8:11 (NWT)

Ask them who is this scripture talking about “Spirit of Him (Jehovah)” this is clearly talking about the Holy Spirit. In their Bible it states “The Holy Spirit raised Jesus from the dead” So from their Bible we can clearly see, Jehovah the Father, Jesus the Son, and the Holy Spirit raised Christ from the dead

19  Go, therefore, and make disciples of people of all the nations,o baptizing themp in the name of the Father and of the Son and of the holy spirit, Matthew 28:19 (NWT)

You can end with the “Great Commision” giving by Christ, why did Jesus feel the need to mention Father, Son, and Holy Spirit? It should aleast plant a seed for the Holy Spirit if they truly care about the truth of God