There is a false teaching in the church that says if someone commits suicide that God will damn that person to hell.
This belief is taken from 1 Corinthians 3:17, which says:
If anyone destroys God’s temple, God will destroy him. For God’s temple is holy, and you are that temple.
As always, the context of a verse determines its meaning.
So what is the context of 1 Corinthians 3:17?
Paul has been writing about those who come into a church and teach on the foundation he laid...a foundation of the death and resurrection of Jesus, grace, the new covenant.