Does 1 Corinthians 2:10-11 teach that the Holy Spirit is omniscient?

The organization known as the "Iglesia Ni Cristo" claims that the Holy Spirit is not God, but instead is a lesser being than both God the Father and Jesus Christ. Is this claim supported by scripture?

1 Corinthians 2:10-11 (ESV) - For the Spirit searches everything, even the depths of God. 11 For who knows a person's thoughts except the spirit of that person, which is in him? So also no one comprehends the thoughts of God except the Spirit of God.

Paul teaches in 1 Corinthians that the Spirit is omniscient, and since only God is omniscient, the Holy Spirit must be God.

The Holy Spirit can search the mind of God

The Spirit searches and knows everything-- including the very thoughts of God! How could a being lesser than God have access to God's very thoughts? No other being knows everything, not even angels, as we see in 1 Peter:

1 Peter 1:12b (ESV) - those who preached the good news to you by the Holy Spirit sent from heaven, things into which angels long to look.

For the Spirit to be omniscient and to have access to all of God's thoughts, the Spirit must be God.

The Holy Spirit is compared to a man's spirit inside him

1 Corinthians 2:11a (ESV) - For who knows a person's thoughts except the spirit of that person, which is in him?

How does a person know his own thoughts? Is it through the help of a lesser being, searching his thoughts? Certainly not! It is through his own spirit inside him. Just as no other man can read a person's thoughts, no other being can read the thoughts of God but God himself! The Spirit of God is indeed God.

Conclusion

The Iglesia Ni Cristo firmly teaches that the Holy Spirit is a lesser being than the Father. However, the bible teaches he opposite: the Spirit is omniscient, and can access the thoughts of God at will. By the grace of God, he shares his Spirit with us to teach us these things:

1 Corinthians 2:10 (ESV) - these things God has revealed to us through the Spirit.

No earthly minister can reveal to us the deep truths of God. Only through the Spirit can we know truth, because only the Spirit knows the mind of God.