Ephesians 2:12 remember that you were at that time separated from Christ, alienated from the commonwealth of Israel and strangers to the covenants of promise, having no hope and without God in the world.
19- So then you are no longer strangers and aliens, but you are fellow citizens with the saints and members of the household of God, built on the foundation of the apostles and prophets, Christ Jesus himself being the cornerstone, in whom the whole structure, being joined together, grows into a holy temple in the Lord. In him you also are being built together into a dwelling place for God by the Spirit.
Without Christ: These are terrible words, and the implications of them are the sum of the woeful condition of the lost man or woman. To be without Christ means to be: without spiritual blessings, light, peace, rest, safety, hope, a place of refuge, purpose, satisfaction, lasting joy, discernment, wisdom, understanding, knowledge, and eternity in Heaven. Look around, be observant, and see if this is not true. Read or listen to almost any news being stated, listen to family, friends, government officials, and people at large, and you will see they lack the peace of God that only comes through Faith in Jesus Christ. In the worst of them, they are greedy, boastful, arrogant, fearful, liars, creating division, confusion, and hatred. In the best of them they are just plain lost and without a solid foundation that can only be found in and through Jesus Christ. They have a form of purpose, peace, satisfaction, and joy, but there is no depth and lasting foundation on which it can stand.
This is exactly where each of us was prior to believing in Jesus Christ. Lost and without eternal hope. We were alienated from God. We were tools of Satan. We were destined to eternal Hell. And, somehow, through God’s grace, mercy, and love, our hearts were softened and our minds understood the gospel, our sinful nature, being separated from God, deserving Hell, and without hope in anything we could do to be made right before God, and we repented from our sin, turned away from self-worthiness and self-reliance, and we trusted in and relied upon Jesus Christ alone, by faith in Him alone.
Paul is saying remember this. You were “without Christ”. In remembering this our hearts and minds should be in constant thankfulness and our lives surrendered to humbly serving Him for the single purpose of honoring and glorifying Him in all we say, think, and do.