You will always have to wait for a period of time after purchasing the policy for sufficient cash value to accumulate for you to borrow against. If the unpaid interest on your loan plus your outstanding loan balance exceeds your policy's total cash value, your policy and all coverage will terminate.
Whole Life enjoys favorable tax treatment.
Cash value growth is generally on a tax-deferred basis, meaning that you pay no interest on any earnings in the policy as long as the policy is in force. Money can be taken out of the policy without having to pay taxes since policy loans are not considered to be taxable income. Withdrawals to the premiums paid can be taken without paying tax. Amounts withdrawn over the premium paid will be taxed when withdrawn. Dividends are paid as a return of premium, and generally reflect the profitability of the company.