Can someone be “undecided” about God the same way someone can be undecided about other things?
It’s possible to be “undecided” on certain issues, such as whether a particular scientific theory is true, or whether a particular conspiracy is true. However, one cannot be undecided about the Christian God. This is because the Christian God is worthy of more than just an acknowledgement of his existence - he is also worthy of worship. Worshipping the Christian God produces a change in one's behaviour. And so a person's behaviour reveals what he or she has decided.
There are other things in life that we cannot be undecided about. For example, a father cannot be “undecided” about whether he will love his children. If he claims to be undecided but ignores his children, then he has, in effect, shown by his actions what his choice is. He has chosen not to love his children. The same type of thing is true of the Christian God. God deserves our love, expressed as worship. So we either live our lives worshipping him or we do not. To be “undecided” about this is to choose not to love God. So, although we can be undecided about the existence of certain gods who don't care about worship (or are not worthy of it), we cannot be undecided about the Christian God.
Short Blog: Why God Cares Whether We Worship Him