Exodus 15:23

And when they came to Marah, they could not drink of the waters of Marah, for they were bitter: therefore the name of it was called Marah.

After three days in the wilderness without drinkable water Israel came to Marah, whose waters were bitter and undrinkable and gave the place its name meaning bitter.
God brought them there on purpose to test whether they would keep trusting Him after their deliverance, to teach them to trust Him as deliverer and leader, and to reveal His power for their good.
They failed the test by murmuring against Moses about what to drink instead of turning to God in faith, thus forgetting Him and losing the blessing the trial was meant to bring.
God in His own power and time made the bitter water sweet and safe to drink by directing Moses to cast in a shrub He had created and placed at hand.
Marah pictures the bitter afflictions of adversity, sickness, disappointment and grief, which are not to be met with unbelieving complaint but with trusting faith that remembers God's past mercies, for when sought He gives help in every trial and a branch of healing that turns bitterness to sweetness.

Arrival at Marah

After three days of travel in the wilderness without water, or without good water, Israel reached Marah. The waters there were bitter and undrinkable, so the people could not drink them. Rather than quenching thirst, the water increased it. The place was called Marah because its name means bitter and identifies its bitterness.

Their coming to Marah was not by chance but on purpose, as part of a great plan to try their faith. The difficult experience was permitted to test whether they had learned trust and obedience from the deliverance in Egypt and at the Red Sea, and whether they would keep trusting God after that deliverance. It was meant to teach them to trust Him as their deliverer and protector and as their invisible leader. God sometimes leads His people into hard, constrained circumstances of adversity, sickness, disappointment and trial because He sees it is for their good, in order to reveal His power and glory in delivering them.

Israel failed the test by murmuring against Moses rather than relying on God and turning to Him in faith. They complained in distrust about what they would drink, thereby forgetting God. By that murmuring they risked and lost the blessing the trial was meant to bring, and the same danger remains to lose the blessing by complaining instead of trusting. The episode continues with God making the water sweet and testing the people, then promising protection from the diseases brought upon Egypt if they obeyed His commands. In doing so God identifies Himself as the one who heals them.

Bitterness Turned Sweet

God made the bitter water sweet and pure so the people could drink safely and with pleasure, in His own time and by His own power and not by any virtue in the tree itself. He directed Moses to cast in a shrub He Himself had created and had already placed at hand for that purpose. The remedy was therefore ready before the need was felt, and the healing came from God who used the means He appointed.

The same desert holds both Marah, with its bitter undrinkable water and desolate rock and sand and hardship, and Elim, with its palms and wells and shade. Bitter and pleasant conditions thus lie close together on the journey. God may turn bitterness to sweetness where His people stand, or He may lead them onward to springs and shelter.

Marah pictures affliction that tastes bitter to the soul. That bitterness includes adversity and sickness and disappointment, grief and hardship, trials and suffering through which God leads His people. Whatever its particular form, it is trial that tests faith and calls for trust.

Such bitterness is not to be met with short-sighted unbelief, murmuring and complaining, for that dishonors God and grieves Christ. It is to be met with clear-eyed, trusting faith that relies on God through trials and looks to Christ's guiding hand. That faith remembers His past love and power and mercies, and expresses gratitude for what He has done with confidence in His continued help, waiting for Him to turn bitterness to sweetness in His own time and for His glory.

When people seek Him, God provides help in every trial and a branch of healing for every bitter experience. Christ helps them recognize healing promises in Scripture, and the Holy Spirit teaches them to receive blessings that answer grief. Jesus' love mingles with sorrow to turn bitterness into comfort and joy and sweetness.

Christ knows all about such trials and is as willing to help in the hour of need as in times past. No tribulation can separate His people from Him. Looking to Him in trusting faith turns the bitterness of Marah into sweetness, for His word is abiding presence even unto the end of the world.

Christ's followers should bring comfort and blessing instead of making life bitter for others. In trial they are to turn from the bitterness to what is precious and bright, especially Jesus' presence, which brings assurance through grace. When others see a Christian endure suffering and face death with Jesus, it gives them strength and courage to keep leading souls to Him.

Both hardship and earthly comfort pass away. The journey that includes Marah ends in the joy of God's everlasting home.