Here are more respectful Jain replies/lines you can use around “Dev–Guru” (honoring the Panch-Parameṣṭhī). Keep them short and traditional.

Very short greetings

• Jai Jinendra.
• Dharma Lābh.
• Śāsan Vijayate.
• Dev–Guru–Dharma kī Jai.
• Vandanā with śuddha bhāv.

Classical invocations (Prakrit/Sanskrit)

• Namo Arihantāṇaṁ. Namo Siddhāṇaṁ. Namo Āyariyāṇaṁ. Namo Uvajjhāyāṇaṁ. Namo Loe Savva–Sāhūṇaṁ.
• Vande Devam, Vande Gurum, Vande Dharmam, Vande Śāsanam.
• Arihantebhyo Namaḥ, Siddhebhyo Namaḥ, Ācāryebhyo Namaḥ, Upādhyāyebhyo Namaḥ, Sarva–Sādhubhyo Namaḥ.

Simple Hindi/Gujarati style lines

• Dev–Guru–Dharma ne vandan, śuddha bhāv sāthe.
• Arihant–Siddha–Āchārya–Upādhyāy–Sādhu ne koṭi-koṭi vandan.
• Ahimsā paramo dharmaḥ — śubha bhāv thi.
• Dev-Guru pāse vinamratāthi namaskār.

Message closers (for texts/notes)

• Michchhāmi Dukkaḍaṁ (use during Kṣamā–Parva / forgiveness context).
• Sadgati kā āśīrvād — śubha mangal.
• Ratnatray āśray se kalyāṇ hoy.

Meaning note (Jain context)

• “Dev” refers to Arihant and Siddha (liberated ones); “Guru” refers to Ācārya, Upādhyāya, and Sādhu. All salutations should preserve this Panch–Parameṣṭhī focus.

If you want a ready reference to core Jain salutations and their meanings, see the Namokār Mantra overview here: