for a string, when natural frequency matches the frequency of the driving oscillations, resonance occurs. in other words, for resonance to happen, the frequency of the driving oscillation must be tuned to match the natural frequency of the string.

when the frequency of our heart is in tune with that of God's..resonance occurs too. and there's an powerful amplicfication. we worship with our heart, tuned to His pleasure, and we touch His heart. not physically but still amplifying what He wants to tell us from His heart. just like resonance.

when the frequency is right, you just know it cos the sound is amplified.
when our heart is rightly tuned, we just know it. cos we will hear Him speak.