And he called the place Massah and Meribah because the Israelites quarrelled and because they tested the Lord saying, ‘Is the Lord among us or not?’

Alec Motyer writes so helpfully about this in ‘The message of Exodus’, p.182, and I simply want to quote him today:

‘The people ‘tested’ the Lord, and he ‘tested’ the people, which according to the Bible are two sides of the same thing. At the place named Massah and Meribah, Psalm 81: 7 (8) says, ‘I tested you at the waters of Meribah, whereas Psalm 95:9 says, ‘your fathers tested and tried me.’ ‘Testing’ God involves putting him on probation, withholding trust pending evidence. For the Israelites it meant doubting whether he who had proved sufficient in the past was still sufficient, now that things had taken a different turn (17:2-3). There is also an element of challenge to God, demanding that he prove his worth all over again: if, against all probabilities, he gets us out of this mess, then we will consider believing, but in the meantime we will suspend faith and obedience. For these reasons ‘testing’ – or in the older translations ‘tempting’ – God is deeply sinful.

When God ‘tests’ us, however, it is a different matter. He does so by bringing us into situations which call for trust and the endurance and obedience that proves our trust is real, so that by the exercise of faith in the face of new challenges, our trust in him can develop and mature until we come to see that everything that happens to us is under divine supervision and is brimful of divine purposes for good.’