What is the ruling on saying or writing "God is mutual love," and what is the ruling on writing words such as "Holy Spirit," "Christianity," "Holy Trinity," "All in God," and "There is no god" to attract non-Muslims to da'wah videos, and is that considered disbelief (kufr)?

It is not permissible for a Muslim to intentionally and voluntarily write blasphemous and atheistic phrases, such as "there is no god." It is not valid to justify this by claiming it is a means of da'wah (proselytizing), for the means of da'wah are numerous, and it is impermissible to use falsehood or writing blasphemy as a means for it. Phrases must be formulated in a proper manner that does not involve affirming falsehood or invalidating truth, such as using an interrogative form like: "Is Allah mutual love?" or "Does the universe have a god?"