The Lord has not forgotten you:
If you have been a Christian for more than a year I would be bold enough to say that you have questioned the Lord’s concern over your life. This may be experienced during suffering, death of loved ones, your wondering if God has a mate for you, a career shift or hunt, and seemingly unfruitful seasons of ministry. The Lord has not forgotten you.
The Lord cannot forget you:
The only thing that God forgets is our sin. (Psalms 103:12) And even then He is not somehow causing our sins against Him to somehow slip his omniscient mind. When God remembers our sin no more, He is not counting it against us anymore. He can do this because He counted our sins against Jesus and He will eternally remember what Jesus did for us.
God cannot forget us because He knows all. God can not unremember you. (Isaiah 40:28 see below, 1 John 3:20)
God cannot forget us because He has promised to never leave us or forsake us. (Deuteronomy 31:8, Matthew 28:20)
God cannot forget us because we are sealed with God the Holy Spirit. (Ephesians 1:13,14)
God cannot forget us because Jesus has purchased us. We belong to God. (1 Corinthians 6:19,20)
The Lord does not want to forget you:
The Lord does not want to forget us because He loves us. (John 3:16) It would be easier for someone to forget to breathe or have the heart pump blood through their veins than for God to not want to love His people. You say that the circulatory system is involuntary and a bad comparison? Well, although the Lord has freely chosen to love us(Ephesians 1:11), in doing so, He is sovereignly and happily bound to do so from within Himself (Numbers 23:19).
The Lord does not want to forget us because in doing so He would be counting the work of Christ and the Holy Spirit as trivial. God the Father loves the Son and Spirit.
The Lord does not want to forget us because we are His children. Even in our proneness to wander and leave the God we love, He manifests His grace and mercy in our lives. (John 1:12)
The Lord does not want to forget us because He does not want to forget our neighbors. In other words, God reaches our neighbors and the nations through His people. He has purchased people from every tongue, tribe and nation. (Revelation 5:9) He does not want to forget about them….He cannot, He will not.
Not only does the Lord not forget us, He is patient with our questions and doubts as He mightily and graciously restores us.
Listen to our merciful God:
Why do you say, O Jacob,
and speak, O Israel,
“My way is hidden from the LORD,
and my right is disregarded by my God”?
Have you not known? Have you not heard?
The LORD is the everlasting God,
the Creator of the ends of the earth.
He does not faint or grow weary;
his understanding is unsearchable.
He gives power to the faint,
and to him who has no might he increases strength.
Even youths shall faint and be weary,
and young men shall fall exhausted;
but they who wait for the LORD shall renew their strength;
they shall mount up with wings like eagles;
they shall run and not be weary;
they shall walk and not faint.
(Isaiah 40:27-31 ESV)