'Strong' in the Bible

be fully capable of comprehending with all the saints (God’s people) the width and length and height and depth of His love [fully experiencing that amazing, endless love];

In conclusion, be strong in the Lord [draw your strength from Him and be empowered through your union with Him] and in the power of His [boundless] might.

With all prayer and petition pray [with specific requests] at all times [on every occasion and in every season] in the Spirit, and with this in view, stay alert with all perseverance and petition [interceding in prayer] for all God’s people.