The dictionary describes a reservoir as
a place where something is kept in store or reserve for later use, or
an artificial lake where water is collected and kept in quantity for
Reservoirs are made to receive – to be filled by higher sources of rivers and streams. If they get very full they can overflow and flood onto the land below. Reservoirs can also get low and even run dry if they don't receive from the higher sources.
Visualize your heart as a reservoir – except this reservoir is designed to receive streams of living water, love, from your Higher Source, God. Our heart reservoir is designed by God to be dependent upon Him as the primary source of love. As long as our reservoir is open and receiving it fills. If our heart reservoir gets very full it overflows and floods of living water pour outward toward others. Unlike man-made reservoirs, we want our reservoirs to flood!
If, on the other hand, our heart reservoir is low, or even empty, we have little or nothing to give. We can try, and we do, but it's such an effort. Our experience is nothing like Jesus describes as living water flowing from within. We may be temporarily motivated by a book or a sermon or a seminar, but it doesn't last. It amounts to what seems like a garden hose to fill our large and empty reservoir. Soon we're struggling again to love and be who Jesus calls us to be. Been there?
A reservoir can't fill itself – it is utterly dependent on the higher sources. We are utterly dependent on God to fill our heart reservoir. We cannot fill the reservoir ourselves, or require someone else to fill it for us, although we often try. Sometimes the rivers or streams that fill a reservoir get clogged or re-routed. In the same way, the River to our heart reservoir can get clogged and re-routed and the flow severely slows down or even stops. God, our Source, is still giving but we're not receiving. We are saved, secure in salvation, but empty of rushing, living water that floods.
The route to our heart reservoir gets clogged when we're in sin. Unconfessed sin clogs the river and prevents our heart from receiving. Fear, shame, guilt, pride, unforgiveness, and unbelief are blockages of the River of Life to our heart. When we choose to confess our sin and receive grace our heart can can receive. When we forgive, from the heart, we allow the River to flow into our heart. When we believe God by trusting His unconditional love we destroy fear, shame, and guilt and allow our heart to receive.
Finally, staying connected in the body of Christ (the Church) is how our reservoirs get filled and how we fill others through the Holy Spirit in us. Don't be deceived into thinking that you can do this on your own - that you don't need the body of Christ or that we don't need you. This is a lie and a way the enemy is dividing us. The Church is God's design for community and interdependence. If you're not in a church (and I mean a local church, not television or radio or Internet church), as messy as they can be, you are limiting, even denying God's design for grace, love, healing, and manifestations of his power.
The enemy of our souls, the devil, is on the prowl to deceive us through pride, shame, fear, and independence. Confess, forgive, receive grace, believe the Truth, and live. Let's allow our heart reservoirs to be filled to overflowing with God's love, the River of Life, so they will overflow and flood the world!