Remember this and stand firm, recall it to mind, you transgressors, remember the former things of old; for I am God, and there is no other; I am God, and there is none like me, declaring the end from the beginning and from ancient times things not yet done, saying, 'My counsel shall stand, and I will accomplish all my purpose,'
Remember God. That is the call to worship to Israel in this passage. Sometimes the deepest experience of real worship is bound up in the command to remember God. What He has done is great. And when we remember His past work, it changes how we live now and what we hope for in our future.
Israel was called to remember a powerful, faithful, covenant-making and covenant-keeping God. Of course, implicit in this reminder would be the awareness that although God had always been faithful, they had sinned in rejecting His faithful love more than once. God was great... Israel? Not so much.
Life is linear. We move along a time scale that explodes into eternity. But while in "the now" it does us good to "remember" our God. The gospel is a historical memory. I trust what God did through Jesus in the past before I ever existed. The gospel shapes my present. I believe it now and it calls me to enjoy life in Christ. The gospel is my future. I must live to let it keep fashioning me to be more like Jesus (I am pathetically far from that) so that I may be with Him forever.