'Strong' in the Bible

Thou therefore, my son, be strong in the grace that is in Christ Jesus.

But God's strong base is unchanging, having this sign, The Lord has knowledge of those who are his: and, Let everyone by whom the name of the Lord is named be turned away from evil.

But keep yourself from those desires of the flesh which are strong when the body is young, and go after righteousness, faith, love, peace, with those whose prayers go up to the Lord from a clean heart.