Benefits of an RSP
You pay less tax. Contributions to an RSP can be deducted from your taxable income, which is especially worthwhile if you use the tax saved to make a contribution for next year or to pay off debts.
Your RSP contribution is tax sheltered. The money you contribute, up to your contribution limit, and the earnings you make on your investments are only subject to tax when you withdraw from your RSP.
You can split your income with a Spousal RSP. Spousal RSP contributions help ensure future retirement income is split evenly between you and your partner.