The very first created sound is OM. In a way the unmanifested God first manifests as OM. So if you want to communicate with God, who is vibrating in this OM sound, you should be able to receive that vibration by tuning your heart radio to the same frequency. The radio should be tuned to the same frequency as the transmitting station. God is transmitting His energy, His beauty, His love, His grace, everything at this OM frequency. If you want to receive it, where should you tune your radio? To the same OM. That is why mantra meditation is a very important practice. All other practices are secondary when compared with mantra repetition. Mantra repetition is a direct way to tune yourself to that cosmic vibration. Even if you don't do any of the other practices you should not miss mantra repetition. That alone will help you a lot. Every day, at cast least times - morning, noon and evening - if not more, you should produce that sound by repeating your mantram. Then you are tuning your radio constantly to stay on a certain wavelength.
OM Shanthi, Shanthi, Shanthi