The B737s (Classic and Next Gen) do not work in the same manner as let's say the B757, B767 and B777. Those airplanes have go-around switches, not TOGA switches. Therefore, it is necessary to hit N1/EPR on the MCP to initiate takeoff mode.
The B737s have the TOGA switches used for Take-off and G/A. Hitting N1 mode on the gnd, as has been stated WILL NOT SET TAKEOFF POWER.
If everyone knew this already, my apologies for chiming in. I just saw that NSEU wrote using the N1 button INSTEAD OF TOGA. There is no substitute for the TOGA switches for initiating a takeoff.