"For this commandment which I command thee this day, it is not hidden from thee, neither is it far off. It is not in Heaven, that thou shouldest say, Who shall go up for us to Heaven, and bring it unto us, that we may hear it, and do it? Neither is it beyond the sea, that thou shouldest say, Who shall go over the sea for us, and bring it to us, that we may hear it, and do it? But the word is very nigh unto thee, in thy mouth, and in thy heart, that thou mayest do it." (Deuteronomy 30:11-14)
Glad and good tidings
In other words, no excuses. Moses shores up any doubt as to what to do by telling the people that God has indeed delivered the best way to go. Any fault as to why one would refuse the words of God, thinking there's some better way, as yet unseen and undelivered, is acting foolishly. This being said, when Paul took this passage one step further by quoting it in his letter to the Romans (10:8) and equating that word, that "commandment" with Jesus, he was ushering in a...new wave. He continues:
"How then shall they call on Him in whom they have not believed? and how shall they believe in Him of whom they have not heard? and how shall they hear without a preacher? And how shall they preach, except they be sent? as it is written, How beautiful are the feet of them that preach the gospel of peace, and bring glad tidings of good things!" (Romans 10:14-15)
There's no telling where you or I am in this process. Telling someone, through word or deed or action, about the saving grace and love of the Lord Jesus Christ is an all-the-time thing. We can propose all sorts of events and instances--that may well be the Holy Spirit showing you "things to come"--but we truly don't know the full effect we have on the people with whom we interact. Have you ever been talking with someone, only to notice a faraway look in their eyes? Sure, upon coming back down to earth, they could reveal the memory or thought you inspired in their heart at that moment. But maybe not. I believe God has been working in everyone's life up till this point and beyond. And the Holy Spirit could have you say just that right thing that will ignite their spirit and give them saving faith. We don't know. Because it's between them and God. And so, living in love and walking in the Spirit (see Galatians 5:16) is the thing to do. None of this "ebbing and flowing" associated with the mercurial tides. Paul (again) continues to the Romans (verse 16a): "But they have not all obeyed the Gospel..."
"Preach the word; be instant in season, out of season; reprove, rebuke, exhort with all longsuffering and doctrine. For the time will come when they will not endure sound doctrine; but after their own lusts shall they heap to themselves teachers, having itching ears; And they shall turn away their ears from the truth, and shall be turned unto fables. But watch thou in all things, endure afflictions, do the work of an evangelist, make full proof of thy ministry." (2 Timothy 4:2-5)
...be instant in season, out of season...
I've always taken that to mean that when you're in the Spirit and you make a mistake, endeavor to heal the breach, confess the sin, whatever, in order to get back in step with the Holy Spirit. As an aside, regarding the moon. Yes, it influences the tides and I know it's been an object of pagan worship the world over. Symbolically, I can't see how that's a good thing. I mean, all the moon does is reflect the light of the sun onto a world shrouded in darkness. Seems to me, the moon is more a symbol of the Body of Christ. And worshiping anything other than God is folly. I digress. When Paul says to Timothy to watch out for certain unsavory character types that aren't aligned with God and His word and His work, he's not kidding. A strain of a lie can be so deeply ingrained into an individual that it could take years to unweave and unravel. Best to remain humble and believe the best of everyone, in love, before leveling accusing eyes. But if God really shows you something...
Both James (1:6-8) and Jude (1:10-13) compare someone who refuses to believe, with a wave. Here one minute, gone the next. They both level harsh and scary judgments at this person, this character type. Barring all that, Paul says "charity", or love "beareth all things, believeth all things, hopeth all things, endureth all things." (1 Corinthians 13:7) The Amplified translates the second instance as "Love is ever ready to believe the best of every person." We really can do no better than that. That's what it means to "walk in the Spirit", to live in love--"in season". If you know someone who doesn't live their faith in spite of professing Christ, God will change them through your prayers. It's never too late. God will bring everyone along who truly wants to ride the waves with Him.