Here, the verb sequence depends on the meaning.

You're perfectly correct that if/then constructions can take the format "If [present tense cause], then [future tense effect]." For example, If you study diligently, you will do well on the GMAT. Studying in the present causes "doing well" in the future.

In this example, though, there is no time differentiation between the children "feeling loved and protected" and "behaving well." Since we are talking about things that are generally true in the present, it makes most sense to use the simple present tense for both verbs. It's perfectly correct to say "If [present tense cause], then [present tense effect]" for circumstances that are generally true.

It's also perfectly correct to invert the order of the if/then construction: "[present tense effect] if [present tense cause]"