Yes, you can bring your spouse to Belgium under a family reunification procedure.
The exact conditions for successfully submitting an application depend heavily on the specific situation. Are you a Belgian national, a European Union citizen, or neither? What nationality does your spouse hold? Are you already married in Belgium, or were you married abroad and does your marriage still need to be recognised in Belgium?
It is not possible to provide a general list of conditions for family reunification. As a general rule of thumb, however, the conditions are less strict if you are a Belgian or an EU citizen. In many cases, you will nevertheless be required to demonstrate that you are able to provide for both your own living expenses and those of your partner. At present, this generally requires a net income of approximately EUR 2,000.00. This amount is linked to the consumer price index and is therefore subject to change.
The same applies to your children, provided that they are still minors. As a rule, family reunification is not available for adult children, except in exceptional circumstances (for example, where adult children are highly dependent on their parents due to their state of health).