1 Peter 4:11
If anyone speaks, he should do it as one speaking the very words of God. If anyone serves, he should do it with the strength God provides, so that in all things God may be praised through Jesus Christ. To him be the glory and the power for ever and ever. Amen.
You are confusing humbly giving credit to God with claiming inspiration from God.
Whatever rutherford believed (I do not wish to be sidetracked onto the side issues) it would have pertained to already written inspired prophecy in the bible. This is not the same as claiming the ability to able to do inspired utterances from God yourself. We are told to decern already written prophecy to see if it is getting fulfilled so as to be prepared. We were given it to use it.
Are you saying we should not try and decern/understand already written bible prophecy?